The Fifth Amendment - takings clause

WEBVTT
Kind: captions
Language: en

00:00:00.297 --> 00:00:02.480
- [Kim] Hi, this is Kim from Khan Academy.

00:00:02.480 --> 00:00:05.350
Today we're learning more
about the takings clause

00:00:05.350 --> 00:00:06.670
of the Fifth Amendment.

00:00:06.670 --> 00:00:08.775
In another video, we'll
discuss the other clauses

00:00:08.775 --> 00:00:10.620
of the Fifth Amendment, those that deal

00:00:10.620 --> 00:00:13.254
with self-incrimination
and due process of law

00:00:13.254 --> 00:00:15.660
but in this video, we're
concentrating on just

00:00:15.660 --> 00:00:18.240
the last few words of the Fifth Amendment

00:00:18.240 --> 00:00:21.511
which forbid the government
from taking private property

00:00:21.511 --> 00:00:24.743
for public use without just compensation.

00:00:24.743 --> 00:00:26.965
To learn more about the takings clause,

00:00:26.965 --> 00:00:29.480
I sought out the help of two experts.

00:00:29.480 --> 00:00:33.120
Richard Epstein is the Laurence
A. Tisch professor of law

00:00:33.120 --> 00:00:36.860
and director of the Classical
Liberal Institute at NYU law.

00:00:36.860 --> 00:00:39.580
He's also a senior fellow
at the Hoover Institution.

00:00:39.580 --> 00:00:43.390
Eduardo Penñalver is the
Allan R. Tessler professor

00:00:43.390 --> 00:00:45.780
and dean of Cornell Law School.

00:00:45.780 --> 00:00:48.550
So Profess Epstein, can you
give us a little background,

00:00:48.550 --> 00:00:50.780
just what is the takings clause?

00:00:50.780 --> 00:00:53.170
- [Richard] Well there's a
rule in constitutional law

00:00:53.170 --> 00:00:55.270
that the shorter the
provision, the more difficult

00:00:55.270 --> 00:00:58.776
the interpretation and this
is a very short petition.

00:00:58.776 --> 00:01:02.270
It says, "nor shall private
property be taken for public use

00:01:02.270 --> 00:01:04.706
"without just compensation,"

00:01:04.706 --> 00:01:08.160
and the first thing to
understand about the clause

00:01:08.160 --> 00:01:11.100
is that it's in the passive
voice so it doesn't tell you

00:01:11.100 --> 00:01:13.936
who's taking it and early
on, since this was part

00:01:13.936 --> 00:01:16.820
of the Bill of Rights,
it was said to apply only

00:01:16.820 --> 00:01:20.180
to congress and not to
the states and then after

00:01:20.180 --> 00:01:23.690
the Civil War through the 14th Amendment,

00:01:23.690 --> 00:01:25.530
it was said to apply to the states.

00:01:25.530 --> 00:01:27.017
So now it applies to both the states

00:01:27.017 --> 00:01:28.990
and to the federal government.

00:01:28.990 --> 00:01:31.180
- [Eduardo] Many constitutions don't have

00:01:31.180 --> 00:01:33.310
an explicit property protection clause

00:01:34.150 --> 00:01:39.129
but there is a fairly strong
norm around compensating

00:01:39.129 --> 00:01:43.686
owners of private property
when you essentially commandeer

00:01:43.686 --> 00:01:47.012
their property for public
purposes and that seems

00:01:47.012 --> 00:01:48.443
to have been the motivation.

00:01:49.373 --> 00:01:51.840
I think the clearest reading of it is

00:01:51.840 --> 00:01:55.450
that it's a provision of the
Constitution that makes clear

00:01:55.450 --> 00:01:59.020
that when the federal
government takes your property

00:01:59.020 --> 00:02:00.870
or when the states take your property

00:02:00.870 --> 00:02:04.530
for some public use that
they have to make you whole

00:02:04.530 --> 00:02:07.060
by giving you just compensation.

00:02:07.060 --> 00:02:09.460
- [Richard] Private property's
a pretty comprehensive term.

00:02:09.460 --> 00:02:11.610
Everybody understands that it means land

00:02:11.610 --> 00:02:13.150
and the things you build on land.

00:02:13.150 --> 00:02:15.950
They also understand that
it tends to cover chattels,

00:02:15.950 --> 00:02:19.520
that is things like books
and baseballs that you happen

00:02:19.520 --> 00:02:22.452
to own and wild animals but it's also,

00:02:22.452 --> 00:02:24.147
it's much broader than that.

00:02:24.147 --> 00:02:26.213
It covers all sorts of intangible rights

00:02:26.213 --> 00:02:29.383
like patents, copyrights, trade secrets.

00:02:29.383 --> 00:02:32.710
These are very complicated
and generally speaking,

00:02:32.710 --> 00:02:34.380
the government doesn't have any obligation

00:02:34.380 --> 00:02:37.180
to create a patent but once
it gives you the patent,

00:02:37.180 --> 00:02:39.730
it just can't take it from
you because the patent,

00:02:39.730 --> 00:02:43.700
after conferred, it is
in fact a property right

00:02:43.700 --> 00:02:45.640
and then it also may or may not cover

00:02:45.640 --> 00:02:48.364
other kinds of intangibles
like good will which is

00:02:48.364 --> 00:02:51.160
the value associated with a business

00:02:51.160 --> 00:02:53.500
knowing that your past
customers may come back

00:02:53.500 --> 00:02:55.110
to you in the future.

00:02:55.110 --> 00:02:56.780
- [Eduardo] On the motives of the framers

00:02:56.780 --> 00:02:59.389
for including this, talk about things like

00:02:59.389 --> 00:03:02.759
the confiscation, mostly
of personal property

00:03:02.759 --> 00:03:06.669
during the Revolutionary War
by the British government

00:03:06.669 --> 00:03:10.350
that that was possibly a
motivation to make clear

00:03:10.350 --> 00:03:13.620
that if in future scenarios,
if the government wanted

00:03:13.620 --> 00:03:16.776
to take your property, it
would have to compensate you.

00:03:16.776 --> 00:03:20.400
Most historians don't think
there was a real problem

00:03:20.400 --> 00:03:24.423
being addressed by this, a
problem of uncompensated taking

00:03:24.423 --> 00:03:27.398
of property by colonial governments

00:03:27.398 --> 00:03:31.670
during that period or
by the state governments

00:03:31.670 --> 00:03:34.150
during the Articles of Confederation.

00:03:34.150 --> 00:03:35.540
- [Richard] The framers wanted a system

00:03:35.540 --> 00:03:37.840
of what we'd call limited government

00:03:37.840 --> 00:03:40.130
and so what the takings
clause essentially says

00:03:40.130 --> 00:03:42.038
is yes we need your land for fort

00:03:42.038 --> 00:03:44.325
and it's really very important

00:03:44.325 --> 00:03:47.360
but if we're gonna take
it and use it for fort,

00:03:47.360 --> 00:03:49.620
that's a public use, we're
gonna pay you compensation

00:03:49.620 --> 00:03:52.073
for the fair market
value of the land before

00:03:52.073 --> 00:03:55.160
the fort was put on and this is in order

00:03:55.160 --> 00:03:56.810
to make sure that you
can't pick and choose

00:03:56.810 --> 00:03:58.580
your victims and it's a way

00:03:58.580 --> 00:04:00.390
of assuring government regularity.

00:04:00.390 --> 00:04:01.590
That's the first.

00:04:01.590 --> 00:04:05.070
Second thing is more economic,
less apparent at the time

00:04:05.070 --> 00:04:06.998
of the framing, pretty apparent today,

00:04:06.998 --> 00:04:09.330
is that the government can take something

00:04:09.330 --> 00:04:11.681
and not pay you compensation,
it's gonna overtake.

00:04:11.681 --> 00:04:16.040
So your land is worth 100
thousand dollars as a farm

00:04:16.040 --> 00:04:18.790
but if you're gonna use it for a fort,

00:04:18.790 --> 00:04:20.710
it's only worth 10 thousand dollars.

00:04:20.710 --> 00:04:22.770
If you don't have to pay
the 100 thousand dollars,

00:04:22.770 --> 00:04:25.060
well you may take it 'cause
you get 10 thousand dollars

00:04:25.060 --> 00:04:27.894
worth of gain but if you have
to pay the fair market value

00:04:27.894 --> 00:04:30.185
of the property interest
taking, you won't do it.

00:04:30.185 --> 00:04:32.867
So essentially what it
does is it makes sure

00:04:32.867 --> 00:04:36.020
or at least improves the
odds that when the government

00:04:36.020 --> 00:04:38.998
does take property, what
does regular, it will in fact

00:04:38.998 --> 00:04:41.048
improve overall social welfare.

00:04:41.048 --> 00:04:43.416
So you have a political function dealing

00:04:43.416 --> 00:04:46.706
with singling out and you
have an economic function

00:04:46.706 --> 00:04:49.040
dealing with the overall improvement

00:04:49.040 --> 00:04:51.757
of government behavior from
an economic point of view.

00:04:51.757 --> 00:04:54.982
- [Kim] Okay so say I had a piece of land

00:04:54.982 --> 00:04:57.454
and the government decided
that they wanted it

00:04:57.454 --> 00:05:00.949
for some purpose, what
would be the legal process

00:05:00.949 --> 00:05:04.464
for the government to go
about acquiring my land?

00:05:04.464 --> 00:05:07.751
- [Eduardo] Well the
process for eminent domain

00:05:07.751 --> 00:05:10.714
really varies by state but
typically there's some notice

00:05:10.714 --> 00:05:13.770
that the government
gives you that it intends

00:05:13.770 --> 00:05:15.030
to take your property.

00:05:15.030 --> 00:05:17.430
The government goes to
court and gets an order

00:05:17.430 --> 00:05:19.960
of condemnation to take
title of the property

00:05:19.960 --> 00:05:22.070
and then often there's a requirement

00:05:22.070 --> 00:05:23.765
that the government bargained with you

00:05:23.765 --> 00:05:25.495
about the value of the property.

00:05:25.495 --> 00:05:27.875
It will tell you what
it thinks the value is,

00:05:27.875 --> 00:05:30.920
the fair market value is
the standard that we use

00:05:30.920 --> 00:05:33.086
for just compensation,
that's the value that

00:05:33.086 --> 00:05:36.823
a willing buyer would
pay to a willing seller

00:05:36.823 --> 00:05:38.370
for the land.

00:05:38.370 --> 00:05:42.184
It doesn't include things
like your sentimental value

00:05:42.184 --> 00:05:44.510
or anything like that so
it's just the market value

00:05:44.510 --> 00:05:45.867
of the property.

00:05:45.867 --> 00:05:47.575
There's some back and forth

00:05:47.575 --> 00:05:49.560
through this required bargaining.

00:05:49.560 --> 00:05:51.540
If the government and the property owner

00:05:51.540 --> 00:05:53.904
can't reach an agreement
then the government

00:05:53.904 --> 00:05:56.924
can go to court and get
the court to specify

00:05:56.924 --> 00:05:58.310
the value of the property
that will be paid

00:05:58.310 --> 00:06:00.970
in compensation and
then the payment is made

00:06:00.970 --> 00:06:04.040
and the deed is transferred
and the government

00:06:04.040 --> 00:06:05.690
becomes the owner of the property.

00:06:05.690 --> 00:06:07.340
- [Kim] Interesting, so the government

00:06:07.340 --> 00:06:09.750
has gone through this process
to try to acquire my land,

00:06:09.750 --> 00:06:12.021
what if I'm a real holdout
and I just really don't want

00:06:12.021 --> 00:06:15.462
the government to get my
land, what happens then?

00:06:15.462 --> 00:06:17.940
- [Eduardo] Well you can
litigate the various pieces

00:06:17.940 --> 00:06:20.180
of this and again, it depends
a little bit on the state law.

00:06:20.180 --> 00:06:23.700
So some states put more
procedural hurdles in the way

00:06:23.700 --> 00:06:24.870
of the government.

00:06:24.870 --> 00:06:27.620
Other states make it
easier for the government

00:06:27.620 --> 00:06:30.870
but under the Constitution,
there are really only two ways

00:06:30.870 --> 00:06:34.080
you can resist the taking of your property

00:06:34.080 --> 00:06:34.913
through eminent domain.

00:06:34.913 --> 00:06:38.730
One is by arguing that the
use that the government plans

00:06:38.730 --> 00:06:41.130
to make of your property
doesn't count as legitimate

00:06:41.130 --> 00:06:43.727
public use because the clause says,

00:06:43.727 --> 00:06:46.377
"nor shall private property
be taken for public use

00:06:46.377 --> 00:06:47.600
"without just compensation,"

00:06:47.600 --> 00:06:49.960
and that public use language
has been interpreted

00:06:49.960 --> 00:06:52.750
to be a limitation on the
power of eminent domain

00:06:52.750 --> 00:06:54.750
and then you can argue, the
second thing you can argue

00:06:54.750 --> 00:06:56.730
is that what the
government is offering you

00:06:56.730 --> 00:07:00.318
in terms of just compensation
is not adequate compensation.

00:07:00.318 --> 00:07:03.350
And you can litigate
those through the courts

00:07:03.350 --> 00:07:05.331
and that can slow the
process down quite a bit.

00:07:05.331 --> 00:07:08.030
Some states make it
easier for the government

00:07:08.030 --> 00:07:10.443
by saying well the government
can actually just take title

00:07:10.443 --> 00:07:15.443
while you're litigating
and others make you go...

00:07:16.813 --> 00:07:20.290
Allow you to stop the condemnation process

00:07:20.290 --> 00:07:24.470
and litigate in advance but
there's often what's called

00:07:24.470 --> 00:07:27.270
a quick take procedure
which allows the government

00:07:27.270 --> 00:07:29.942
to move more quickly
and put the litigation

00:07:29.942 --> 00:07:32.914
on the backend but the
public use, if it's found,

00:07:32.914 --> 00:07:35.050
if the use if found not
to be public, what you win

00:07:35.050 --> 00:07:38.790
is an actual prohibition
on the taking itself.

00:07:38.790 --> 00:07:39.810
You keep your property.

00:07:39.810 --> 00:07:42.130
If you win on the just compensation side,

00:07:42.130 --> 00:07:44.871
all you get is more money,
they still take your property.

00:07:44.871 --> 00:07:47.410
- [Kim] So you mentioned public use.

00:07:47.410 --> 00:07:49.850
What counts as public use?

00:07:49.850 --> 00:07:51.770
- [Eduardo] Well under the current law,

00:07:51.770 --> 00:07:55.360
any use that generates a public benefit

00:07:55.360 --> 00:07:57.191
is really a public use.

00:07:57.191 --> 00:08:00.900
The way the court has put it
is anything the government,

00:08:00.900 --> 00:08:03.814
any purpose the government can pursue

00:08:03.814 --> 00:08:07.240
through any other means, it can pursue

00:08:07.240 --> 00:08:08.890
through eminent domain.

00:08:08.890 --> 00:08:12.290
So if the government wants to create jobs

00:08:12.290 --> 00:08:14.841
or if the government wants to beautify

00:08:14.841 --> 00:08:18.377
or if the government
wants to remove blight,

00:08:18.377 --> 00:08:21.060
all those things are things
that we think it's legitimate

00:08:21.060 --> 00:08:22.990
for the government to try to do.

00:08:22.990 --> 00:08:25.271
If it can do those things,
it can do them through

00:08:25.271 --> 00:08:27.278
the use of the eminent domain power.

00:08:27.278 --> 00:08:30.240
- [Kim] One thing that
strikes me as interesting

00:08:30.240 --> 00:08:32.094
is just the fact that this clause

00:08:32.094 --> 00:08:36.021
is in the Fifth Amendment among things

00:08:36.021 --> 00:08:40.410
like double jeopardy or self-incrimination

00:08:40.410 --> 00:08:42.670
so why do you think the framers included

00:08:42.670 --> 00:08:45.940
this particular clause here as opposed

00:08:45.940 --> 00:08:47.656
to elsewhere in the Bill of Rights?

00:08:47.656 --> 00:08:49.360
- [Richard] Well that's a great question

00:08:49.360 --> 00:08:51.316
to which there's no obvious
answer but the one clause

00:08:51.316 --> 00:08:55.190
that is pretty close to it
is the due process clause

00:08:55.190 --> 00:08:56.987
in the Fifth Amendment that says,

00:08:56.987 --> 00:08:59.177
"nor shall any person be deprived of life,

00:08:59.177 --> 00:09:01.531
"liberty or property
without due process of law."

00:09:01.531 --> 00:09:04.155
So if you start with the procedural stuff,

00:09:04.155 --> 00:09:07.150
somebody's gonna say well how do we know

00:09:07.150 --> 00:09:08.662
that the procedures aren't fair?

00:09:08.662 --> 00:09:11.030
And if it turns out
that the government uses

00:09:11.030 --> 00:09:14.061
a set of procedures that don't
give you adequate notice,

00:09:14.061 --> 00:09:16.342
you're always going to end up short

00:09:16.342 --> 00:09:19.024
on the amount of compensation
that you're gonna require.

00:09:19.024 --> 00:09:22.670
So bad procedures tend
to lead to bad outcomes

00:09:22.670 --> 00:09:25.060
which tend to lead to property being taken

00:09:25.060 --> 00:09:26.599
at less than full market value.

00:09:26.599 --> 00:09:29.662
So what happens is is
therefore very close linkage

00:09:29.662 --> 00:09:33.783
between the procedures used
under the due process clause

00:09:33.783 --> 00:09:37.553
and the substantive protection
that you have under takings.

00:09:37.553 --> 00:09:39.627
- [Kim] Any changes in the interpretation

00:09:39.627 --> 00:09:42.740
of the takings clause by
the Supreme Court over time?

00:09:42.740 --> 00:09:45.540
- [Richard] Well there's
been a huge kind of switch up

00:09:45.540 --> 00:09:48.520
and down and let me put
it the following way.

00:09:48.520 --> 00:09:50.920
In the beginning, there
wasn't much of anything

00:09:50.920 --> 00:09:52.983
that was done with respect
to the takings clause.

00:09:52.983 --> 00:09:55.760
The first federal case to deal with it

00:09:55.760 --> 00:09:59.398
was called Barron against
Baltimore in 1833 or so

00:09:59.398 --> 00:10:03.797
and it just simply said that
the clause does not allow

00:10:03.797 --> 00:10:07.560
for protection of Mr.
Barron against the city

00:10:07.560 --> 00:10:09.890
of Baltimore because it only binds

00:10:09.890 --> 00:10:12.520
the federal government,
it doesn't bind the state.

00:10:12.520 --> 00:10:15.584
After the Civil War, two things happen,

00:10:15.584 --> 00:10:19.190
a real distinction, the first
thing is you start getting

00:10:19.190 --> 00:10:22.166
comprehensive regulation of the railroads

00:10:22.166 --> 00:10:25.333
and the rates they can charge
and then public utilities

00:10:25.333 --> 00:10:27.610
and the rates that they can charge.

00:10:27.610 --> 00:10:30.820
And then in 1921, there's a
case called Block v. Hersch

00:10:30.820 --> 00:10:33.098
and it's a very close 5-4 decision

00:10:33.098 --> 00:10:36.530
but they sustain on the
grounds that it's a wartime,

00:10:36.530 --> 00:10:39.390
a temporary two year statute
that limits the rents

00:10:39.390 --> 00:10:41.770
that can be charged in Washington D.C.

00:10:41.770 --> 00:10:43.645
at the end of the first World War.

00:10:43.645 --> 00:10:45.247
- [Eduardo] One of the biggest changes

00:10:45.247 --> 00:10:46.180
in the interpretation
of the takings clause

00:10:47.602 --> 00:10:48.470
was the extension of the takings clause

00:10:49.311 --> 00:10:51.491
to government situations
in which your property

00:10:51.491 --> 00:10:53.170
was not appropriated by the government.

00:10:53.170 --> 00:10:55.830
So what we call the
regulatory takings doctrine

00:10:55.830 --> 00:11:00.830
which started in with the
case of Pennsylvania Coal

00:11:01.330 --> 00:11:06.261
versus Mayhon in the 1920s
and then has now become

00:11:06.261 --> 00:11:08.320
much more, it was sort
of dormant for a while

00:11:08.320 --> 00:11:11.699
but become much more
active since the 1980s,

00:11:11.699 --> 00:11:13.587
that's a doctrine that says,

00:11:13.587 --> 00:11:16.471
"if the government regulates
your use of property

00:11:16.471 --> 00:11:20.167
"excessively, then the
courts can treat that

00:11:20.167 --> 00:11:22.677
"in effect as a confiscation
of your property

00:11:22.677 --> 00:11:24.818
"and require the payment
of just compensation."

00:11:24.818 --> 00:11:27.400
That's maybe the most significant change

00:11:27.400 --> 00:11:30.405
in the interpretation of
the clause in its history.

00:11:30.405 --> 00:11:32.640
So there continues to be controversy

00:11:32.640 --> 00:11:34.980
about the public use doctrine
on modern commentators,

00:11:34.980 --> 00:11:37.711
especially libertarians, who
want a very narrowly drawn

00:11:37.711 --> 00:11:42.310
account of public use and
disagree with the breadth

00:11:42.310 --> 00:11:44.474
of the doctrine as I described it to you.

00:11:44.474 --> 00:11:47.680
So there's a lot of activism around that.

00:11:47.680 --> 00:11:49.940
There's been some state
law that's been enacted

00:11:49.940 --> 00:11:52.180
to try to raise the floor there.

00:11:52.180 --> 00:11:54.742
The federal definition of
public use is just a floor

00:11:54.742 --> 00:11:56.840
and states can go beyond that and restrict

00:11:56.840 --> 00:11:59.268
the power of eminent
domain more forcefully

00:11:59.268 --> 00:12:00.977
if they want to and they have.

00:12:00.977 --> 00:12:03.670
- [Kim] So we've learned
that the takings clause

00:12:03.670 --> 00:12:05.567
of the Fifth Amendment
prevents both federal

00:12:05.567 --> 00:12:07.934
and state governments from
taking private property

00:12:07.934 --> 00:12:10.575
for public use without just compensation

00:12:10.575 --> 00:12:14.740
but there are a lot of
questions about what counts

00:12:14.740 --> 00:12:18.284
as private property, public
use or just compensation.

00:12:18.284 --> 00:12:21.200
In recent years, debate
over the takings clause

00:12:21.200 --> 00:12:23.340
has centered on whether
government regulations

00:12:23.340 --> 00:12:26.000
about how a private
individual can use land

00:12:26.000 --> 00:12:28.819
also constitute a form of
compensation and the extent

00:12:28.819 --> 00:12:31.980
of acceptable public uses for which

00:12:31.980 --> 00:12:33.830
the government can seize property.

00:12:33.830 --> 00:12:35.620
To learn more about the Fifth Amendment,

00:12:35.620 --> 00:12:37.796
visit the National Constitution
Center's interactive

00:12:37.796 --> 00:12:40.500
constitution and Khan Academy's resources

00:12:40.500 --> 00:12:42.353
on U.S. government and politics.


The Third Amendment

WEBVTT
Kind: captions
Language: en

00:00:00.360 --> 00:00:02.460
- [Kim] Hi, this is Kim from Khan Academy

00:00:02.460 --> 00:00:05.600
and today, I'm learning more
about the Third Amendment

00:00:05.600 --> 00:00:08.370
to the U.S. Constitution,
which states that

00:00:08.370 --> 00:00:11.460
no soldier shall, in time of peace,

00:00:11.460 --> 00:00:15.160
be quartered in any house
without the consent of the owner,

00:00:15.160 --> 00:00:19.760
nor in time of war, but in a
manner to be prescribed by law.

00:00:19.760 --> 00:00:22.370
This amendment clearly
draws its inspiration

00:00:22.370 --> 00:00:25.470
from the Quartering Acts that
caused a great deal of tension

00:00:25.470 --> 00:00:27.830
between the American
colonies and Great Britain

00:00:27.830 --> 00:00:29.700
leading up to the American Revolution.

00:00:29.700 --> 00:00:32.700
But does it have any
relevance to our lives today?

00:00:32.700 --> 00:00:35.820
To learn more, I sought out
the help of two experts.

00:00:35.820 --> 00:00:37.940
Jay Wexler is a Professor of Law

00:00:37.940 --> 00:00:40.330
at Boston University School of Law

00:00:40.330 --> 00:00:44.170
specializing in Constitutional
Law and the Supreme Court.

00:00:44.170 --> 00:00:46.520
Glenn Reynolds is the Beauchamp Brogan

00:00:46.520 --> 00:00:48.030
Distinguished Professor of Law

00:00:48.030 --> 00:00:51.010
at the University of
Tennessee College of Law.

00:00:51.010 --> 00:00:53.710
So Professor Reynolds, why did the framers

00:00:53.710 --> 00:00:55.560
feel it was necessary
to put this amendment

00:00:55.560 --> 00:00:57.520
in the Bill of Rights?

00:00:57.520 --> 00:01:00.550
- [Glenn] Well, we don't
think of quartering of troops

00:01:00.550 --> 00:01:02.950
in people's homes as a
very big issue these days,

00:01:02.950 --> 00:01:03.920
and of course, some people would say

00:01:03.920 --> 00:01:06.030
that's because the Third
Amendment's worked perfectly.

00:01:06.030 --> 00:01:09.320
If only the rest of the Bill
of Rights worked so well.

00:01:09.320 --> 00:01:11.070
But it was a big issue for the framers

00:01:11.070 --> 00:01:13.300
because it had happened a lot.

00:01:13.300 --> 00:01:15.210
To the framers, the English civil wars

00:01:15.210 --> 00:01:17.650
of the 17th century were recent history,

00:01:17.650 --> 00:01:20.360
and their attitudes were
very much shaped by that.

00:01:20.360 --> 00:01:22.220
And the Stuart kings, in particular,

00:01:22.220 --> 00:01:23.560
used quartering of troops

00:01:23.560 --> 00:01:26.970
as a way to punish towns and
areas that they didn't like.

00:01:26.970 --> 00:01:31.239
The soldiers back then were
basically jail sweepings.

00:01:31.239 --> 00:01:33.530
They had a tendency to steal and to rape

00:01:33.530 --> 00:01:35.220
and to get into fights

00:01:35.220 --> 00:01:37.270
even with the people
they were quartered with.

00:01:37.270 --> 00:01:40.800
So to have troops quartered upon a town

00:01:40.800 --> 00:01:43.160
was a way of sort of mass punishment,

00:01:43.160 --> 00:01:47.270
and that made the English rather unhappy.

00:01:47.270 --> 00:01:50.210
And after the Glorious Revolution,

00:01:50.210 --> 00:01:52.110
they banned the practice in England,

00:01:52.110 --> 00:01:54.010
but they did not ban it in the colony.

00:01:54.010 --> 00:01:55.750
- [Jay] The king had quartered troops

00:01:55.750 --> 00:01:57.960
in the private homes in the colonies

00:01:57.960 --> 00:02:00.090
in what became the United States

00:02:00.090 --> 00:02:01.630
for a long time before the Revolution,

00:02:01.630 --> 00:02:06.120
since at least 1670 and,
as it's easy to imagine,

00:02:06.120 --> 00:02:08.710
this caused a lot of tension
between the homeowners

00:02:08.710 --> 00:02:11.670
in the colonies and the British troops.

00:02:11.670 --> 00:02:15.470
And then it got even worse
as we found ourselves

00:02:15.470 --> 00:02:18.870
in the French and Indian
War in the 1750s and 1760s.

00:02:18.870 --> 00:02:20.570
'Cause nobody wants the government

00:02:20.570 --> 00:02:22.100
to put troops in their house.

00:02:22.100 --> 00:02:24.400
The house is the place where people

00:02:24.400 --> 00:02:25.690
live their most private lives,

00:02:25.690 --> 00:02:27.390
and to have the government
come in and then say,

00:02:27.390 --> 00:02:29.980
here, the soldiers are gonna
live here with you now,

00:02:29.980 --> 00:02:31.470
is something that, understandably,

00:02:31.470 --> 00:02:34.640
the colonists were very worried about

00:02:34.640 --> 00:02:35.900
and didn't like very much.

00:02:35.900 --> 00:02:38.870
So, things got worse in the 1760s,

00:02:38.870 --> 00:02:42.890
when England passed the
first Quartering Act,

00:02:42.890 --> 00:02:44.550
which basically required that colonies

00:02:44.550 --> 00:02:46.990
had to provide barracks
for the king's troops

00:02:46.990 --> 00:02:47.920
and if there weren't barracks,

00:02:47.920 --> 00:02:51.570
then the soldiers were
authorized to live in

00:02:51.570 --> 00:02:53.733
inns and alehouses and houses,

00:02:54.940 --> 00:02:56.540
this is right from the Act itself,

00:02:56.540 --> 00:02:59.730
selling rum and brandy and strong water.

00:02:59.730 --> 00:03:01.900
And then, if there weren't
enough of those around,

00:03:01.900 --> 00:03:03.740
they could live in private buildings,

00:03:03.740 --> 00:03:06.270
uninhabited houses and
barns and things like this

00:03:06.270 --> 00:03:09.880
and then that requirement
resulted, in part,

00:03:09.880 --> 00:03:13.150
in the Stamp Act of 1765 which led then

00:03:13.150 --> 00:03:15.070
to the Tea Party, which
everybody knows about,

00:03:15.070 --> 00:03:18.410
and the Tea Party really
made the king angry.

00:03:18.410 --> 00:03:21.960
After that, the king passed,
or the parliament passed

00:03:21.960 --> 00:03:24.000
the second Quartering Act of 1774

00:03:24.000 --> 00:03:26.540
which required colonists to allow

00:03:26.540 --> 00:03:29.040
the king's troops to live in their homes

00:03:29.040 --> 00:03:30.690
which was, of course, something

00:03:30.690 --> 00:03:32.980
that the colonists
absolutely couldn't stand.

00:03:32.980 --> 00:03:36.650
So, when we got our independence,

00:03:36.650 --> 00:03:39.780
it was one of the most important goals

00:03:39.780 --> 00:03:41.620
of the framers to make sure

00:03:41.620 --> 00:03:43.700
that this kind of thing could not happen.

00:03:43.700 --> 00:03:45.780
- [Kim] So, what was so problematic

00:03:45.780 --> 00:03:48.760
about the possibility of having a soldier

00:03:48.760 --> 00:03:50.870
quartered in your home,
or multiple soldiers

00:03:50.870 --> 00:03:52.630
quartered in your home?

00:03:52.630 --> 00:03:54.500
- [Jay] Well, some of us
don't particularly like

00:03:54.500 --> 00:03:56.980
having house guests in
general, (chuckling)

00:03:56.980 --> 00:03:58.960
but they're not house guests.

00:03:58.960 --> 00:04:01.300
I mean, the problem is, troops back then

00:04:01.300 --> 00:04:04.340
were not like, we think of soldiers today

00:04:04.340 --> 00:04:05.950
in the American army, it's
hard to get in the army.

00:04:05.950 --> 00:04:07.600
You know, people try to get in the army

00:04:07.600 --> 00:04:09.470
and they're told, go away,
your grades aren't good enough

00:04:09.470 --> 00:04:11.120
and you're not smart enough.

00:04:11.120 --> 00:04:13.130
And if you have a criminal
record, they don't want you.

00:04:13.130 --> 00:04:14.950
It wasn't like that back then.

00:04:14.950 --> 00:04:16.810
Warfare was bloody and awful.

00:04:16.810 --> 00:04:20.020
The troops stood in masses a
hundred yards from each other

00:04:20.020 --> 00:04:23.700
and blasted away with
these Brown Bess muskets.

00:04:23.700 --> 00:04:25.430
Actually the most common injury then was

00:04:25.430 --> 00:04:27.550
when pieces of the soldier next to you

00:04:27.550 --> 00:04:30.820
were driven into you,
jawbone and stuff like that.

00:04:30.820 --> 00:04:33.140
So, it was pretty nasty and the discipline

00:04:33.140 --> 00:04:35.430
that it took to make people
do that was pretty harsh

00:04:35.430 --> 00:04:37.960
and it wasn't very appealing
to the better sort,

00:04:37.960 --> 00:04:41.170
so, literally, a lot of these soldiers

00:04:41.170 --> 00:04:43.580
were people who would sent
there straight from jail.

00:04:43.580 --> 00:04:45.160
So, they were not very nice people to have

00:04:45.160 --> 00:04:47.600
living in your house and they didn't

00:04:47.600 --> 00:04:49.660
have a very good attitude when they did.

00:04:49.660 --> 00:04:52.300
- [Jay] I think they were widely viewed

00:04:52.300 --> 00:04:56.150
as being cruel, as being unfriendly,

00:04:56.150 --> 00:04:59.600
maybe even drunk a lot, but
it was certainly not the case

00:04:59.600 --> 00:05:03.360
that they were making their own beds

00:05:03.360 --> 00:05:08.050
and cleaning up after their
dinner and such like that.

00:05:08.050 --> 00:05:10.580
So, they were not guests.

00:05:10.580 --> 00:05:13.890
So, they were people who
were living in the houses,

00:05:13.890 --> 00:05:16.700
taking liberties any way they wanted

00:05:16.700 --> 00:05:21.320
and making a basically a
nuisance of themselves, for sure.

00:05:21.320 --> 00:05:24.160
So, I mean, imagine if some
soldier you didn't know

00:05:24.160 --> 00:05:25.830
and you didn't invite into your house

00:05:25.830 --> 00:05:27.550
was all of a sudden staying
in your living room,

00:05:27.550 --> 00:05:30.590
and then multiply that
by however many soldiers

00:05:30.590 --> 00:05:33.593
it might be, 10, who knows,
living in your living room

00:05:33.593 --> 00:05:35.250
while you're trying to carry out

00:05:35.250 --> 00:05:38.100
the daily tasks of your life
and talking with your children

00:05:38.100 --> 00:05:41.630
and making plans about dinner and

00:05:41.630 --> 00:05:44.390
can you imagine how
offensive that would be

00:05:44.390 --> 00:05:45.890
and how problematic that would be

00:05:45.890 --> 00:05:47.610
to have the government's troops

00:05:47.610 --> 00:05:49.620
hanging out in your living room.

00:05:49.620 --> 00:05:51.750
It would be pretty awful,
so it's no surprise

00:05:51.750 --> 00:05:54.480
that the framers, I
think, objected to this

00:05:54.480 --> 00:05:58.500
and put this amendment
into the Constitution.

00:05:58.500 --> 00:06:02.520
- [Kim] So, do you think that
the Quartering Act of 1774,

00:06:02.520 --> 00:06:03.730
do you think that was the straw

00:06:03.730 --> 00:06:06.320
that broke the camel's back
in the American Revolution?

00:06:06.320 --> 00:06:07.740
Was it that living with soldiers

00:06:07.740 --> 00:06:11.730
was so noxious that it
propelled the colonists

00:06:11.730 --> 00:06:14.110
over the edge into the Revolution?

00:06:14.110 --> 00:06:15.510
- [Jay] Well, there were a lot of straws

00:06:15.510 --> 00:06:17.780
that broke that camel's
back so it's hard to say

00:06:17.780 --> 00:06:19.590
which one, but I think one of the things

00:06:19.590 --> 00:06:21.700
that the colonists hated about it was

00:06:21.700 --> 00:06:23.940
that they were being subjected to a rule

00:06:23.940 --> 00:06:25.380
that didn't apply in England

00:06:25.380 --> 00:06:27.680
and one of things they
revolted for, remember,

00:06:27.680 --> 00:06:29.740
was they thought they'd been
deprived of what they called

00:06:29.740 --> 00:06:32.110
the rights of Englishmen and
this was just another example

00:06:32.110 --> 00:06:35.400
of the crown feeling free
to do things in the colonies

00:06:35.400 --> 00:06:36.850
that he wouldn't do at home and

00:06:36.850 --> 00:06:38.510
that sent a signal to the colonists

00:06:38.510 --> 00:06:39.820
that you're not as important,

00:06:39.820 --> 00:06:41.410
you're not full blown citizens,

00:06:41.410 --> 00:06:42.780
we don't care about you as much

00:06:42.780 --> 00:06:44.290
and you don't have the same rights.

00:06:44.290 --> 00:06:46.620
And I think that was what
was intolerable about it.

00:06:46.620 --> 00:06:49.330
- [Kim] So this seems like an amendment

00:06:49.330 --> 00:06:53.430
that has this very specific
historical background,

00:06:53.430 --> 00:06:56.130
but how does this kind of
play forward into the future?

00:06:56.130 --> 00:06:59.350
Was there any danger
that there might be later

00:06:59.350 --> 00:07:00.840
quartering of soldiers

00:07:00.840 --> 00:07:04.010
after the framing of the Constitution?

00:07:04.010 --> 00:07:05.550
- [Jay] Well, there was always the risk,

00:07:05.550 --> 00:07:08.910
there was always the risk
that even in the independent

00:07:08.910 --> 00:07:11.680
United States that the
government might, at some point,

00:07:11.680 --> 00:07:14.560
require homeowners to put up soldiers

00:07:14.560 --> 00:07:15.820
and, in fact, there is some evidence

00:07:15.820 --> 00:07:18.080
that during the Civil War this happened.

00:07:18.080 --> 00:07:21.120
I think the evidence is a little foggy,

00:07:21.120 --> 00:07:24.300
but there is certainly a
suggesting in the literature

00:07:24.300 --> 00:07:26.990
that the Union government
required homeowners

00:07:26.990 --> 00:07:28.920
to put up Union troops.

00:07:28.920 --> 00:07:31.450
And so, it could have been a problem.

00:07:31.450 --> 00:07:34.470
It's not something that has, in fact,

00:07:34.470 --> 00:07:37.040
turned into a huge issue over time,

00:07:37.040 --> 00:07:38.840
which might say something
about how successful

00:07:38.840 --> 00:07:41.393
the Third Amendment has
been in our history.

00:07:42.350 --> 00:07:45.000
But, it was always a risk
and I think it was never far

00:07:45.000 --> 00:07:46.850
from the minds of the
framers, this possibility

00:07:46.850 --> 00:07:50.010
that the government might
decide to put its soldiers

00:07:50.010 --> 00:07:51.470
into people's private homes.

00:07:51.470 --> 00:07:53.890
- [Kim] I think, at the
time of the Revolution

00:07:53.890 --> 00:07:58.580
and when the framers were putting
together the Constitution,

00:07:58.580 --> 00:08:03.580
they had a real fear of
standing armies, right?

00:08:03.600 --> 00:08:05.190
They didn't want a standing army

00:08:05.190 --> 00:08:06.820
in the United States and, in fact,

00:08:06.820 --> 00:08:09.230
there wasn't one in the
United States at all,

00:08:09.230 --> 00:08:14.230
a professional army until
after the Civil War, I believe.

00:08:15.162 --> 00:08:18.300
And now we see a standing army,

00:08:18.300 --> 00:08:20.020
a very large standing army

00:08:20.020 --> 00:08:23.280
of the United States
as being pretty normal.

00:08:23.280 --> 00:08:24.780
How do you think the Third Amendment

00:08:24.780 --> 00:08:27.190
shows how our ideas of standing armies

00:08:27.190 --> 00:08:28.810
have changed over time?

00:08:28.810 --> 00:08:30.180
- [Glenn] You know, one historian said

00:08:30.180 --> 00:08:32.790
that our framers had an almost panic fear

00:08:32.790 --> 00:08:34.840
of standing armies and
that was based, again,

00:08:34.840 --> 00:08:38.420
on the history of the English
civil wars in the 17th century

00:08:38.420 --> 00:08:41.050
where standing armies, the tradition was,

00:08:41.050 --> 00:08:42.670
the king would disarm
people he didn't like

00:08:42.670 --> 00:08:44.580
and then use the army against them

00:08:44.580 --> 00:08:46.330
and that was seen as very bad,

00:08:46.330 --> 00:08:48.600
the standing armies were seen
as somebody whose loyalty,

00:08:48.600 --> 00:08:51.280
who paid them, not to the country.

00:08:51.280 --> 00:08:53.980
I think our army has had
a different trajectory.

00:08:53.980 --> 00:08:56.870
I mean, really we didn't
have a large standing army

00:08:56.870 --> 00:08:58.920
in the United States on a regular basis

00:08:58.920 --> 00:09:00.750
until after World War II.

00:09:00.750 --> 00:09:02.210
So, I think we're just less afraid of it

00:09:02.210 --> 00:09:04.580
because our army has
been more professional,

00:09:04.580 --> 00:09:06.890
maybe because we feel like the army

00:09:06.890 --> 00:09:10.163
is more loyal to citizens
than it is to who pays it.

00:09:11.320 --> 00:09:14.440
Or maybe because we've just lost, perhaps,

00:09:14.440 --> 00:09:17.860
a vital edge of paranoia
that the framers had.

00:09:17.860 --> 00:09:20.440
- [Kim] Has there ever
been a Supreme Court case

00:09:20.440 --> 00:09:23.960
that ruled based on the Third Amendment?

00:09:23.960 --> 00:09:26.740
- [Glenn] There's a single
federal court of appeals case

00:09:26.740 --> 00:09:30.057
called Engblomb against Carey where the

00:09:30.057 --> 00:09:33.592
federal court of appeals
applied the Third Amendment

00:09:33.592 --> 00:09:36.280
in a New York prison riot case where

00:09:37.400 --> 00:09:39.500
guards were pushed out of their barracks

00:09:39.500 --> 00:09:41.890
and National Guardsmen were put in.

00:09:41.890 --> 00:09:43.290
But the Supreme Court's never done it.

00:09:43.290 --> 00:09:45.170
But the Supreme Court has
relied on the Third Amendment.

00:09:45.170 --> 00:09:47.410
In fact, one of the most famous cases

00:09:47.410 --> 00:09:49.120
of the second half of the 20th century

00:09:49.120 --> 00:09:51.850
from the Warren Court was
Griswold against Connecticut.

00:09:51.850 --> 00:09:53.750
That was actually a
case striking down laws

00:09:53.750 --> 00:09:55.030
against birth control.

00:09:55.030 --> 00:09:56.040
- [Jay] Which is one of the forerunners

00:09:56.040 --> 00:09:58.160
to Roe vs Wade and in that
case, the Supreme Court

00:09:58.160 --> 00:10:01.184
was trying to figure
out if the Constitution

00:10:01.184 --> 00:10:03.970
encompassed a right to privacy

00:10:03.970 --> 00:10:07.480
and Justice Douglass wrote this opinion

00:10:07.480 --> 00:10:10.970
which said that there
were kind of penumbras

00:10:12.020 --> 00:10:14.870
or emanations from a variety of amendments

00:10:14.870 --> 00:10:16.510
in the Bill of Rights,
the Fourth Amendment,

00:10:16.510 --> 00:10:19.140
the First Amendment, and
importantly, the Third Amendment,

00:10:19.140 --> 00:10:20.850
that suggested that the Constitution

00:10:20.850 --> 00:10:23.740
does protect privacy
rights to some degree.

00:10:23.740 --> 00:10:25.058
That was kind of the high point

00:10:25.058 --> 00:10:27.950
for the Third Amendment
in Supreme Court history

00:10:27.950 --> 00:10:31.575
and even in the cases that
followed the Griswold decision,

00:10:31.575 --> 00:10:35.820
which found, for example,
the right to an abortion,

00:10:35.820 --> 00:10:38.530
et cetera, the Court did not rely on

00:10:38.530 --> 00:10:41.280
that Third Amendment penumbra theory.

00:10:41.280 --> 00:10:43.730
So, it was one case the Supreme Court

00:10:43.730 --> 00:10:46.550
cited the Third Amendment
as being the source

00:10:46.550 --> 00:10:51.550
of a sort of enigmatic privacy right.

00:10:52.650 --> 00:10:54.390
Other than that, the
Supreme Court has really not

00:10:54.390 --> 00:10:55.840
touched the Third Amendment ever.

00:10:55.840 --> 00:10:59.400
- [Kim] So, there's kind of a suggestion

00:10:59.400 --> 00:11:01.190
of the right to privacy

00:11:01.190 --> 00:11:03.010
that goes along with the Third Amendment

00:11:03.010 --> 00:11:05.520
and also, perhaps, the Fourth Amendment.

00:11:05.520 --> 00:11:06.370
Do you think that's the way

00:11:06.370 --> 00:11:08.480
that the Third Amendment is, perhaps,

00:11:08.480 --> 00:11:10.173
most relevant to us now?

00:11:11.150 --> 00:11:12.110
- [Glenn] Well, it could be.

00:11:12.110 --> 00:11:13.270
I mean, there's been some thought,

00:11:13.270 --> 00:11:15.110
there've been some law review articles

00:11:15.110 --> 00:11:17.700
and other speculation on
this that, for example,

00:11:17.700 --> 00:11:19.710
when the government installs spyware

00:11:19.710 --> 00:11:21.040
on your computer at home,

00:11:21.040 --> 00:11:23.080
that's the equivalent of
quartering troops in your house

00:11:23.080 --> 00:11:25.690
because somebody is inside
your house spying on you

00:11:26.780 --> 00:11:28.950
and breaking the privacy, sort of like

00:11:28.950 --> 00:11:30.450
having to have a soldier at home.

00:11:30.450 --> 00:11:32.480
No court's held that, as far as I know,

00:11:32.480 --> 00:11:35.640
but it's not crazy and there
have been a few other cases

00:11:36.920 --> 00:11:38.600
more on point where people claim

00:11:38.600 --> 00:11:41.020
that when police SWAT
teams took over their homes

00:11:41.020 --> 00:11:43.900
to look down on the neighbors and such,

00:11:43.900 --> 00:11:45.120
that that was troop quartering,

00:11:45.120 --> 00:11:47.380
but courts so far have said
that that's not the same thing

00:11:47.380 --> 00:11:49.500
since they're not actually sleeping there.

00:11:49.500 --> 00:11:51.050
- [Jay] One possibility is to say, hey,

00:11:51.050 --> 00:11:53.103
the Third Amendment really plays no role.

00:11:54.150 --> 00:11:56.890
The courts don't talk
about it, nobody really

00:11:56.890 --> 00:11:59.670
knows much about what it says.

00:11:59.670 --> 00:12:01.150
And so it's really not important.

00:12:01.150 --> 00:12:03.480
On the other hand, you could argue,

00:12:03.480 --> 00:12:06.530
and I'd suggest that this is
probably a plausible argument,

00:12:06.530 --> 00:12:09.060
that, in fact, the Third
Amendment has done a lot.

00:12:09.060 --> 00:12:11.020
The fact that you don't see cases

00:12:11.020 --> 00:12:14.310
about quartering of troops
may very well indicate

00:12:14.310 --> 00:12:17.000
how well the Third Amendment is serving.

00:12:17.000 --> 00:12:21.210
So, the Third Amendment just is quiet

00:12:21.210 --> 00:12:24.398
but that's because it's
doing its job so well.

00:12:24.398 --> 00:12:26.850
And that nobody comes and tries
to quarter troops in there,

00:12:26.850 --> 00:12:28.450
in anybody's houses and if they did,

00:12:28.450 --> 00:12:30.080
they would immediately lose.

00:12:30.080 --> 00:12:32.970
So, you could argue from that perspective

00:12:32.970 --> 00:12:34.970
that the Third Amendment
is one of the most powerful

00:12:34.970 --> 00:12:36.130
and well working amendments

00:12:36.130 --> 00:12:37.819
that we have in the Constitution.

00:12:37.819 --> 00:12:38.652
One thing that's interesting

00:12:38.652 --> 00:12:40.060
about the Constitutional history

00:12:40.060 --> 00:12:42.830
is that sometimes we see
parts of the Constitution

00:12:42.830 --> 00:12:44.950
that have been dormant
for a really long time

00:12:44.950 --> 00:12:47.530
all of a sudden pop up into consciousness

00:12:47.530 --> 00:12:50.146
either because the courts
have started reading them

00:12:50.146 --> 00:12:53.160
differently or because the
facts of the world change

00:12:53.160 --> 00:12:54.890
and so all of a sudden the amendment

00:12:54.890 --> 00:12:57.550
or other Constitutional
provision seems relevant.

00:12:57.550 --> 00:13:00.150
And that could potentially
happen with the Third Amendment

00:13:00.150 --> 00:13:01.900
and what I would site here

00:13:01.900 --> 00:13:04.790
are two developments in the world.

00:13:04.790 --> 00:13:07.470
One is that we see these days the police

00:13:07.470 --> 00:13:10.010
becoming more militarized and so it looks

00:13:10.010 --> 00:13:14.010
kind of like the police
are soldiers in a way

00:13:14.010 --> 00:13:16.140
when they come all armed and with their,

00:13:16.140 --> 00:13:18.050
and armored vehicles and such.

00:13:18.050 --> 00:13:20.490
And the second phenomenon is kind of the

00:13:20.490 --> 00:13:22.200
increased surveillance that we're seeing

00:13:22.200 --> 00:13:25.740
from the government into
private phone conversations,

00:13:25.740 --> 00:13:28.927
private computer files,
and things like that,

00:13:28.927 --> 00:13:31.620
and so it's possible that we, a court

00:13:31.620 --> 00:13:34.990
at some point, might
think that the government

00:13:34.990 --> 00:13:39.080
is violating if not the
letter, but then the spirit

00:13:39.080 --> 00:13:42.430
of the Third Amendment by basically

00:13:42.430 --> 00:13:46.300
engaging in the 21st century
version of quartering

00:13:46.300 --> 00:13:50.000
by monitoring people's communications

00:13:50.000 --> 00:13:53.540
within the home in a
kind of militaristic way.

00:13:53.540 --> 00:13:55.630
- [Kim] So, we've learned
that the Third Amendment

00:13:55.630 --> 00:13:58.200
prevents the government
from quartering soldiers

00:13:58.200 --> 00:14:01.350
in the homes of American
citizens and that, in fact,

00:14:01.350 --> 00:14:03.720
it does such a good the Supreme Court

00:14:03.720 --> 00:14:06.610
has only made one decision
using the Third Amendment

00:14:06.610 --> 00:14:08.660
as its primary basis.

00:14:08.660 --> 00:14:12.510
But, the Third Amendment's
implied guarantee of privacy

00:14:12.510 --> 00:14:15.310
in the home may come to be more important

00:14:15.310 --> 00:14:16.560
as we debate the limits

00:14:16.560 --> 00:14:19.180
of government surveillance
of our computers.

00:14:19.180 --> 00:14:21.200
To learn more about the Third Amendment,

00:14:21.200 --> 00:14:23.220
visit the National Constitution Center's

00:14:23.220 --> 00:14:26.670
interactive Constitution
and Khan Academy's resources

00:14:26.670 --> 00:14:28.553
on U.S. government and politics.


Limits of combined functions

WEBVTT
Kind: captions
Language: en

00:00:00.450 --> 00:00:02.730
- [Instructor] Let's
find the limit of f of x

00:00:02.730 --> 00:00:07.670
times h of x as x approaches zero.

00:00:07.670 --> 00:00:09.640
All right, we have graphical depictions

00:00:09.640 --> 00:00:12.800
of the graphs y equals f
of x and y equals h of x.

00:00:12.800 --> 00:00:14.303
And we know, from our limit properties,

00:00:14.303 --> 00:00:17.917
that this is going to be
the same thing as the limit

00:00:17.917 --> 00:00:21.960
as x approaches zero of f of x

00:00:21.960 --> 00:00:23.880
times,

00:00:23.880 --> 00:00:25.770
times the limit

00:00:27.000 --> 00:00:30.330
as x approaches zero of

00:00:30.330 --> 00:00:32.180
h of x.

00:00:32.180 --> 00:00:34.040
And let's think about
what each of these are.

00:00:34.040 --> 00:00:37.460
So let's first think about
f of x right over here.

00:00:37.460 --> 00:00:40.870
So on f of x, as x approaches zero,

00:00:40.870 --> 00:00:43.700
notice the function itself
isn't defined there.

00:00:43.700 --> 00:00:45.920
But we see when we approach from the left,

00:00:45.920 --> 00:00:47.770
we are approaching the,

00:00:47.770 --> 00:00:49.730
the function seems to
be approaching the value

00:00:49.730 --> 00:00:51.740
of negative one right over here.

00:00:51.740 --> 00:00:54.480
And as we approach from the
right, the function seems

00:00:54.480 --> 00:00:58.950
to be approaching the
value of negative one.

00:00:58.950 --> 00:01:00.210
So the limit here,

00:01:00.210 --> 00:01:02.510
this limit here is negative one.

00:01:02.510 --> 00:01:03.343
As we approach from the left,

00:01:03.343 --> 00:01:04.310
we're approaching negative one.

00:01:04.310 --> 00:01:06.160
As we approach from the right,
the value of the function

00:01:06.160 --> 00:01:08.400
seems to be approaching negative one.

00:01:08.400 --> 00:01:10.210
Now what about h of x?

00:01:10.210 --> 00:01:12.340
Well, h of x we have down here.

00:01:12.340 --> 00:01:14.910
As x approaches zero,

00:01:14.910 --> 00:01:17.070
as x approaches zero,

00:01:17.070 --> 00:01:19.660
the function is defined at x equals zero.

00:01:19.660 --> 00:01:22.423
It looks like it is equal to one.

00:01:23.336 --> 00:01:25.190
And the limit is also equal to one.

00:01:25.190 --> 00:01:27.710
We can see that, as we
approach it from the left,

00:01:27.710 --> 00:01:29.250
we are approaching one.

00:01:29.250 --> 00:01:31.570
As we approach from the
right, we're approaching one.

00:01:31.570 --> 00:01:33.990
As we approach x equals zero
from the left, we approach,

00:01:33.990 --> 00:01:35.340
the function approaches one.

00:01:35.340 --> 00:01:37.500
As we approach x equals
zero from the right,

00:01:37.500 --> 00:01:39.800
the function itself is approaching one.

00:01:39.800 --> 00:01:42.830
And it makes sense that the
function is defined there,

00:01:42.830 --> 00:01:44.500
is defined at x equals zero,

00:01:44.500 --> 00:01:47.280
and the limit as x approaches zero

00:01:47.280 --> 00:01:49.130
is equal to the same as the,

00:01:49.130 --> 00:01:51.800
is equal to the value of
the function at that point

00:01:51.800 --> 00:01:54.240
because this is a continuous function.

00:01:54.240 --> 00:01:55.960
So this is,

00:01:55.960 --> 00:01:56.980
this is one.

00:01:56.980 --> 00:01:59.890
And so negative one times one

00:01:59.890 --> 00:02:02.370
is going to be equal to,

00:02:02.370 --> 00:02:04.770
is equal to negative one.

00:02:04.770 --> 00:02:07.460
So that is equal to negative one.

00:02:07.460 --> 00:02:08.453
Let's do one more.

00:02:10.220 --> 00:02:12.460
All right, so these are both,

00:02:12.460 --> 00:02:14.070
looks like continuous functions.

00:02:14.070 --> 00:02:16.410
So we have the limit as x
approaches zero of h of x

00:02:16.410 --> 00:02:17.940
over g of x.

00:02:17.940 --> 00:02:20.590
So once again, using our limit properties,

00:02:20.590 --> 00:02:25.310
this is going to be the same
thing as the limit of h of x

00:02:25.310 --> 00:02:27.890
as x approaches zero

00:02:27.890 --> 00:02:30.290
over the limit

00:02:30.290 --> 00:02:32.020
of g of x

00:02:32.020 --> 00:02:34.710
as x approaches zero.

00:02:34.710 --> 00:02:37.690
Now what's the limit of h
of x as x approaches zero?

00:02:37.690 --> 00:02:39.040
This is, let's see,

00:02:39.040 --> 00:02:40.960
as we approach zero from the left,

00:02:40.960 --> 00:02:42.830
as we approach x equals
zero from the left,

00:02:42.830 --> 00:02:44.680
our function seems to be approaching four.

00:02:44.680 --> 00:02:47.740
And as we approach x
equals zero from the right,

00:02:47.740 --> 00:02:50.300
our function seems to be approaching four.

00:02:50.300 --> 00:02:51.190
That's also what the value

00:02:51.190 --> 00:02:52.840
of the function is at x equals zero.

00:02:52.840 --> 00:02:54.550
That makes sense because this
is a continuous function.

00:02:54.550 --> 00:02:57.270
So the limit as we approach x
equals zero should be the same

00:02:57.270 --> 00:03:00.040
as the value of the
function at x equals zero.

00:03:00.040 --> 00:03:02.630
So this top, this is going to be four.

00:03:02.630 --> 00:03:05.220
Now let's think about the
limit of g of x as x equals,

00:03:05.220 --> 00:03:07.170
as x approaches zero.

00:03:07.170 --> 00:03:10.350
So from the left, it looks
like, as x approaches zero,

00:03:10.350 --> 00:03:12.480
the value of the function
is approaching zero.

00:03:12.480 --> 00:03:14.800
And as x approaches zero from the right,

00:03:14.800 --> 00:03:17.250
the value of the function
is also approaching zero,

00:03:17.250 --> 00:03:18.970
which happens to also be,

00:03:18.970 --> 00:03:21.560
which also happens to be g of zero.

00:03:21.560 --> 00:03:22.840
G of zero is also zero.

00:03:22.840 --> 00:03:24.800
And that makes sense that the
limit and the actual value

00:03:24.800 --> 00:03:26.550
of the function at that point is the same

00:03:26.550 --> 00:03:28.070
because it's continuous.

00:03:28.070 --> 00:03:30.600
So this also is zero,

00:03:30.600 --> 00:03:32.150
but now we're in a strange situation.

00:03:32.150 --> 00:03:34.560
We have to take four
and divide it by zero.

00:03:34.560 --> 00:03:36.640
So this limit will not exist

00:03:36.640 --> 00:03:39.190
'cause we can't take four
and divide it by zero.

00:03:39.190 --> 00:03:42.400
So even though the limit
of h of x is x equals,

00:03:42.400 --> 00:03:43.670
as x approaches zero exists

00:03:43.670 --> 00:03:47.180
and the limit of g of x as
x approaches zero exists,

00:03:47.180 --> 00:03:49.490
we can't divide four by zero,

00:03:49.490 --> 00:03:52.563
so this whole entire limit does not exist,

00:03:54.217 --> 00:03:55.050
does not exist.

00:03:56.430 --> 00:03:59.790
And actually, if you were
to plot h of x over g of x,

00:03:59.790 --> 00:04:02.100
if you were to plot that graph,

00:04:02.100 --> 00:04:03.500
you would see it even clearer

00:04:03.500 --> 00:04:05.200
that that limit does not exist.

00:04:05.200 --> 00:04:07.650
You would actually be able
to see it graphically.


Changes in the AD-AS Model and the Phillips curve

WEBVTT
Kind: captions
Language: en

00:00:00.580 --> 00:00:02.150
- [Instructor] In this
video, we're gonna build

00:00:02.150 --> 00:00:04.030
on what we already know
about aggregate demand

00:00:04.030 --> 00:00:06.800
and aggregate supply,
and the Phillips curve,

00:00:06.800 --> 00:00:09.420
and we are going to connect these ideas.

00:00:09.420 --> 00:00:10.900
So first, the Phillips curve.

00:00:10.900 --> 00:00:13.300
This is a typical Phillips
curve for an economy.

00:00:13.300 --> 00:00:16.060
High inflation is associated
with low unemployment,

00:00:16.060 --> 00:00:19.900
high unemployment is
associated with low inflation,

00:00:19.900 --> 00:00:21.700
but we can really view this curve

00:00:21.700 --> 00:00:24.210
as the short run Phillips curve.

00:00:24.210 --> 00:00:26.520
Short run Phillips curve.

00:00:26.520 --> 00:00:29.060
We might sit at different
points on this curve

00:00:29.060 --> 00:00:31.150
at different points in an economic cycle,

00:00:31.150 --> 00:00:32.950
but we could also introduce an idea

00:00:32.950 --> 00:00:35.340
known as a long run Phillips curve,

00:00:35.340 --> 00:00:37.900
which is just based on the natural rate

00:00:37.900 --> 00:00:39.860
of unemployment for this economy.

00:00:39.860 --> 00:00:41.650
So let's say the natural
rate of unemployment

00:00:41.650 --> 00:00:44.260
for this economy is 6%.

00:00:44.260 --> 00:00:46.340
So, then our long run Phillips curve

00:00:46.340 --> 00:00:49.560
would just be a vertical
line right over there.

00:00:49.560 --> 00:00:52.640
Long run Phillips curve.

00:00:52.640 --> 00:00:54.150
Now why is it a vertical line?

00:00:54.150 --> 00:00:56.990
Well it says in the long
run, our natural rate

00:00:56.990 --> 00:00:58.880
of unemployment is 6%

00:00:58.880 --> 00:01:02.140
regardless of what the
inflation rate might be.

00:01:02.140 --> 00:01:04.670
And so if we are sitting
at the intersection

00:01:04.670 --> 00:01:07.090
of these two curves, that means

00:01:07.090 --> 00:01:09.660
that our economy right
in this moment in time

00:01:09.660 --> 00:01:12.220
is operating at full employment.

00:01:12.220 --> 00:01:14.700
If unemployment was lower than that,

00:01:14.700 --> 00:01:16.690
it would be overheating to some degree,

00:01:16.690 --> 00:01:18.560
and if unemployment were higher than that,

00:01:18.560 --> 00:01:21.000
then we would have a negative output gap.

00:01:21.000 --> 00:01:22.500
But how do we tie these ideas

00:01:22.500 --> 00:01:24.870
to aggregate demand and aggregate supply?

00:01:24.870 --> 00:01:29.010
Well let's draw our long
run aggregate supply curve,

00:01:29.010 --> 00:01:30.750
and I'm gonna do it
right at the intersection

00:01:30.750 --> 00:01:34.060
of our aggregate demand and
short run aggregate supply curve

00:01:34.060 --> 00:01:36.810
for now, because I wanna show an economy

00:01:36.810 --> 00:01:39.340
that's operating at its full potential.

00:01:39.340 --> 00:01:43.850
So here, this is our long
run aggregate supply,

00:01:43.850 --> 00:01:45.490
and once again it's a vertical line

00:01:45.490 --> 00:01:48.400
because in the long run,
regardless of the price level,

00:01:48.400 --> 00:01:50.650
we have a certain output for this economy

00:01:50.650 --> 00:01:51.870
that is sustainable.

00:01:51.870 --> 00:01:54.380
So that is our full employment.

00:01:54.380 --> 00:01:55.940
I'll do F, period, E, period.

00:01:55.940 --> 00:01:57.690
That's our full employment output.

00:01:57.690 --> 00:01:59.870
Anything more than
that, it's unsustainable

00:01:59.870 --> 00:02:02.030
based on where the economy
is structurally right now,

00:02:02.030 --> 00:02:03.710
and anything less than that,

00:02:03.710 --> 00:02:06.410
is you have a negative output gap.

00:02:06.410 --> 00:02:08.220
But now let's think
about what would happen

00:02:08.220 --> 00:02:10.160
if we start shifting curves around.

00:02:10.160 --> 00:02:13.600
What if we were to have
a negative demand shock?

00:02:13.600 --> 00:02:17.750
So our aggregate demand
curve shifts to the left.

00:02:17.750 --> 00:02:20.020
Well in that world, and
this is all a review,

00:02:20.020 --> 00:02:22.280
you can see that your equilibrium price,

00:02:22.280 --> 00:02:25.110
so I'm gonna call this
aggregate demand sub two,

00:02:25.110 --> 00:02:29.620
our price level two, and
our new equilibrium output

00:02:29.620 --> 00:02:31.610
for our economy sub two.

00:02:31.610 --> 00:02:33.500
You can see that both are lower.

00:02:33.500 --> 00:02:35.770
We now have a negative output gap.

00:02:35.770 --> 00:02:38.050
But what would that correspond to here

00:02:38.050 --> 00:02:40.500
on our Phillips curves?

00:02:40.500 --> 00:02:42.740
Well, when you have a negative output gap,

00:02:42.740 --> 00:02:45.120
you're likely to have higher unemployment.

00:02:45.120 --> 00:02:47.750
And shifts in aggregate in
the aggregate demand curve

00:02:47.750 --> 00:02:50.700
would be movements along the
short run Phillips curve.

00:02:50.700 --> 00:02:52.990
So we're gonna move along
the short run Phillips curve,

00:02:52.990 --> 00:02:54.860
and we're going to have
higher unemployment,

00:02:54.860 --> 00:02:56.930
'cause we have a negative output gap.

00:02:56.930 --> 00:02:59.210
So we might get to that
point right over there.

00:02:59.210 --> 00:03:01.290
So I'll just call that point sub two.

00:03:01.290 --> 00:03:03.820
So we went from a situation where before,

00:03:03.820 --> 00:03:05.660
we had 6% unemployment,

00:03:05.660 --> 00:03:09.090
and let's say we had 3% inflation,

00:03:09.090 --> 00:03:12.380
to a world where maybe now, we have,

00:03:12.380 --> 00:03:15.050
I don't know, let's
call it 9% unemployment,

00:03:15.050 --> 00:03:19.330
and now we have 2% inflation.

00:03:19.330 --> 00:03:20.740
And it could go the other way around.

00:03:20.740 --> 00:03:22.290
Let's say we were
starting from our original

00:03:22.290 --> 00:03:26.040
aggregate demand curve and you
have a positive demand shock,

00:03:26.040 --> 00:03:29.760
and so now you could go to this curve,

00:03:29.760 --> 00:03:33.340
aggregate demand three, and so here,

00:03:33.340 --> 00:03:36.550
our equilibrium price level is higher.

00:03:36.550 --> 00:03:38.070
It's called P sub three.

00:03:38.070 --> 00:03:39.960
And our equilibrium output,

00:03:39.960 --> 00:03:43.670
we have a positive output
gap, so Y sub three.

00:03:43.670 --> 00:03:45.310
And that would correspond to,

00:03:45.310 --> 00:03:46.940
if we have a positive output gap,

00:03:46.940 --> 00:03:48.670
that means we have very low unemployment,

00:03:48.670 --> 00:03:50.520
maybe unsustainably low unemployment.

00:03:50.520 --> 00:03:52.870
So we might be right over here.

00:03:52.870 --> 00:03:55.350
So this might be a situation
where our unemployment rate,

00:03:55.350 --> 00:03:58.520
let's say that's about, I don't know, 4%.

00:03:58.520 --> 00:04:01.220
And now our inflation, this might be,

00:04:01.220 --> 00:04:04.300
let's call that 4% as well.

00:04:04.300 --> 00:04:06.220
And something interesting happens

00:04:06.220 --> 00:04:09.120
as you start to have higher
and higher inflation.

00:04:09.120 --> 00:04:12.300
That can lead to people just
having higher expectations

00:04:12.300 --> 00:04:15.870
for price and higher expectations
for inflation itself.

00:04:15.870 --> 00:04:19.900
And if folks have higher
expectations for inflation,

00:04:19.900 --> 00:04:21.560
well then they might wanna charge more

00:04:21.560 --> 00:04:23.610
for a certain level of output.

00:04:23.610 --> 00:04:25.640
So let's say at this level of output,

00:04:25.640 --> 00:04:28.280
people might want to have
a higher price level.

00:04:28.280 --> 00:04:30.150
At this level of output,
people might wanna have

00:04:30.150 --> 00:04:33.180
a higher level price,
a higher price level.

00:04:33.180 --> 00:04:34.970
And so it could actually shift

00:04:34.970 --> 00:04:37.890
our short run aggregate supply up,

00:04:37.890 --> 00:04:39.880
or you could say to the left.

00:04:39.880 --> 00:04:44.650
So short run aggregate supply,
I'll call that sub three.

00:04:44.650 --> 00:04:47.220
Now when the short run aggregate supply

00:04:47.220 --> 00:04:50.440
gets shifted to the
left in this situation,

00:04:50.440 --> 00:04:54.160
notice we're back to our
full employment output,

00:04:54.160 --> 00:04:57.030
but our price level is now much higher.

00:04:57.030 --> 00:04:59.810
Now what would that
correspond to over here?

00:04:59.810 --> 00:05:00.820
Well when you have a shift

00:05:00.820 --> 00:05:03.370
in short run aggregate supply curves,

00:05:03.370 --> 00:05:05.090
that would actually lead to a shift

00:05:05.090 --> 00:05:07.340
in your short run Phillips curve,

00:05:07.340 --> 00:05:09.000
but which way would it shift?

00:05:09.000 --> 00:05:10.560
Well another way to think about it is,

00:05:10.560 --> 00:05:12.950
at a given, just as at
a given level of output

00:05:12.950 --> 00:05:14.310
you would've expected a higher price

00:05:14.310 --> 00:05:16.800
because of this increased
inflation expectations,

00:05:16.800 --> 00:05:19.310
so here, at a given level of unemployment,

00:05:19.310 --> 00:05:22.650
you would expect a higher
level of inflation.

00:05:22.650 --> 00:05:26.020
So, our curve, you would say
shifts up or to the right.

00:05:26.020 --> 00:05:29.036
So we would then have a short run

00:05:29.036 --> 00:05:32.350
Phillips curve that looks like this.

00:05:32.350 --> 00:05:34.310
I'll call that sub three.

00:05:34.310 --> 00:05:37.030
And we might get back to this point.

00:05:37.030 --> 00:05:39.650
Well for sure if were at
this full employment output,

00:05:39.650 --> 00:05:41.450
then we are operating in our natural rate

00:05:41.450 --> 00:05:43.100
of unemployment again, but notice,

00:05:43.100 --> 00:05:45.080
now our inflation has crept even higher.

00:05:45.080 --> 00:05:48.140
This might be 5% inflation.

00:05:48.140 --> 00:05:50.180
Now the last thing you
might be wondering about

00:05:50.180 --> 00:05:53.520
is when do these long
run curves ever shift?

00:05:53.520 --> 00:05:54.810
Well we've talked about it before

00:05:54.810 --> 00:05:57.050
when we talked about long
run aggregate supply,

00:05:57.050 --> 00:06:01.400
and that shifts if the economy
structurally changes somehow.

00:06:01.400 --> 00:06:03.300
Let's say our factories get bombed out

00:06:03.300 --> 00:06:06.480
in a war or something, then
this should shift to the left.

00:06:06.480 --> 00:06:10.200
And if we got better
technology, or better ways

00:06:10.200 --> 00:06:12.540
of organizing ourselves,
or more resources,

00:06:12.540 --> 00:06:14.300
this might shift to the right.

00:06:14.300 --> 00:06:17.650
Similarly, if there's a
massive shift in global trade,

00:06:17.650 --> 00:06:20.650
and maybe our workers' skills
aren't as valuable anymore

00:06:20.650 --> 00:06:24.000
in the global economy, this
long run Phillips curve

00:06:24.000 --> 00:06:25.780
might shift to the right.

00:06:25.780 --> 00:06:28.410
If all of a sudden we are
able to, or over time,

00:06:28.410 --> 00:06:30.120
we're able to get people more skilled,

00:06:30.120 --> 00:06:32.500
maybe we get frictional unemployment down

00:06:32.500 --> 00:06:35.100
because we have better
technology to place people,

00:06:35.100 --> 00:06:37.453
well that might shift this to the left.


Worked free response question on unemployment

WEBVTT
Kind: captions
Language: en

00:00:00.270 --> 00:00:02.060
- [Instructor] We are
told the following table

00:00:02.060 --> 00:00:05.500
shows labor-market data for Country X.

00:00:05.500 --> 00:00:07.350
And they tell us how many are employed,

00:00:07.350 --> 00:00:09.430
frictionally unemployed,
structurally unemployed,

00:00:09.430 --> 00:00:13.000
cyclically unemployed, and
also not in the labor force.

00:00:13.000 --> 00:00:15.760
So this first question here
and actually we skipped part a

00:00:15.760 --> 00:00:18.610
because we want all of these
to focus on our labor force,

00:00:18.610 --> 00:00:22.030
so calculate the unemployment
rate in Country X.

00:00:22.030 --> 00:00:23.980
Show your work.

00:00:23.980 --> 00:00:26.874
So pause this video and see
if you can work through that.

00:00:26.874 --> 00:00:31.720
All right so our unemployment
rate is going to be equal to

00:00:31.720 --> 00:00:35.643
our number unemployed, unemployed,

00:00:36.730 --> 00:00:38.630
which is going to be the sum
of the frictionally unemployed,

00:00:38.630 --> 00:00:40.860
structurally unemployed,
and cyclically unemployed,

00:00:40.860 --> 00:00:44.470
divided by our total labor force.

00:00:44.470 --> 00:00:45.680
So our labor force is going to be

00:00:45.680 --> 00:00:47.650
our employed plus unemployed.

00:00:47.650 --> 00:00:52.650
So it's going to be
number employed, employed,

00:00:53.250 --> 00:00:57.293
plus number unemployed, unemployed.

00:00:58.570 --> 00:01:00.740
And we want to express
this as a percentage,

00:01:00.740 --> 00:01:02.725
and since they're asking
us to show our work,

00:01:02.725 --> 00:01:05.650
we could even put that there, times 100%.

00:01:05.650 --> 00:01:08.360
It never hurts to give more
clarity when someone asks you

00:01:08.360 --> 00:01:10.310
to show your work.

00:01:10.310 --> 00:01:11.700
And so what's this going to be?

00:01:11.700 --> 00:01:14.257
Our number unemployed
is going to be 10,000

00:01:14.257 --> 00:01:17.730
plus 5,000 plus 5,000, actually
let me just write this,

00:01:17.730 --> 00:01:21.900
10K plus five K plus five K,

00:01:21.900 --> 00:01:25.560
over our employed is 180K,

00:01:25.560 --> 00:01:28.778
and then our number unemployed
is going to be plus 10K,

00:01:28.778 --> 00:01:33.778
plus five K plus five K, times 100%,

00:01:34.490 --> 00:01:38.160
which is equal to in our
numerator, we have 20,000.

00:01:38.160 --> 00:01:39.610
I'll just write it out here.

00:01:39.610 --> 00:01:43.803
20,000, our denominator
we have 200,000, 200,000,

00:01:47.190 --> 00:01:48.997
times 100%.

00:01:50.140 --> 00:01:53.210
And so this is going to
all, this is going to be

00:01:53.210 --> 00:01:57.100
0.10, and then times 100%,

00:01:57.100 --> 00:02:01.570
this is going to be equal
to a 10% unemployment rate.

00:02:01.570 --> 00:02:04.750
All right now part c,
calculate the labor force

00:02:04.750 --> 00:02:07.720
participation rate in Country X.

00:02:07.720 --> 00:02:08.700
Show your work.

00:02:08.700 --> 00:02:11.060
So once again, pause the
video and see if you can

00:02:11.060 --> 00:02:11.893
figure that out.

00:02:12.840 --> 00:02:14.050
So let's just remind ourselves

00:02:14.050 --> 00:02:16.610
what our labor force participation is.

00:02:16.610 --> 00:02:21.610
It is going to be our
labor force, labor force,

00:02:21.620 --> 00:02:23.890
we could say number in the labor force,

00:02:23.890 --> 00:02:27.630
and then over our total
eligible population.

00:02:27.630 --> 00:02:32.163
So you could say number in
or I would say labor force,

00:02:34.834 --> 00:02:38.430
labor force, plus not in labor force,

00:02:38.430 --> 00:02:42.940
plus the number not in labor force.

00:02:42.940 --> 00:02:44.750
And you might say, well when your,

00:02:44.750 --> 00:02:46.710
this denominator is the
eligible population,

00:02:46.710 --> 00:02:48.000
who's not eligible?

00:02:48.000 --> 00:02:49.960
Well it would be people
who are not of working age,

00:02:49.960 --> 00:02:51.530
it might be people who are incarcerated

00:02:51.530 --> 00:02:53.870
or institutionalized in some way,

00:02:53.870 --> 00:02:55.500
could be people in the military.

00:02:55.500 --> 00:02:58.070
So then and of course we wanna
express this as a percentage,

00:02:58.070 --> 00:03:00.860
so write times 100%,

00:03:00.860 --> 00:03:03.320
is equal to,

00:03:03.320 --> 00:03:06.510
so our labor force is going
to be all of the employed

00:03:06.510 --> 00:03:08.220
or unemployed people.

00:03:08.220 --> 00:03:11.030
So this is going to be, it's
essentially this denominator

00:03:11.030 --> 00:03:12.150
right over here,

00:03:12.150 --> 00:03:14.460
so it's going to be 200,000.

00:03:14.460 --> 00:03:16.180
That's our labor force.

00:03:16.180 --> 00:03:21.020
Divided by our labor
force which is 200,000

00:03:21.020 --> 00:03:22.740
plus the not in the labor force,

00:03:22.740 --> 00:03:24.750
so that's 100,000,

00:03:24.750 --> 00:03:27.590
and of course times 100%.

00:03:27.590 --> 00:03:32.170
And this is going to be
equal to 2/3 times 100%,

00:03:32.170 --> 00:03:35.420
and so we could write 66.7,

00:03:35.420 --> 00:03:39.427
it would be 66.6 repeating, but 66.7%

00:03:40.430 --> 00:03:42.950
is our labor force participation rate.

00:03:42.950 --> 00:03:44.110
Fair enough.

00:03:44.110 --> 00:03:45.500
Now part d.

00:03:45.500 --> 00:03:47.560
Draw a correctly labeled graph

00:03:47.560 --> 00:03:50.800
of the production possibilities
curve for Country X,

00:03:50.800 --> 00:03:53.130
with consumer goods on the horizontal axis

00:03:53.130 --> 00:03:55.190
and capital goods on the vertical axis.

00:03:55.190 --> 00:03:58.140
Indicate a point on your graph, labeled Z,

00:03:58.140 --> 00:04:00.240
that reflects the current
level of unemployment.

00:04:00.240 --> 00:04:02.870
Pause your video and
see if you can do that.

00:04:02.870 --> 00:04:03.980
All right now let's do that together.

00:04:03.980 --> 00:04:07.980
I'll scroll down a little bit
so I have space to do that.

00:04:07.980 --> 00:04:12.980
So they tell us with consumer
goods on the horizontal axis,

00:04:13.160 --> 00:04:14.180
so let me do it like that.

00:04:14.180 --> 00:04:19.120
So my horizontal axis, I'm
going to have consumer goods,

00:04:19.120 --> 00:04:24.120
consumer goods, and then
they say capital goods

00:04:24.840 --> 00:04:26.253
on the vertical axis.

00:04:27.620 --> 00:04:30.103
So it might look something like this.

00:04:31.120 --> 00:04:36.120
This is capital goods, capital goods,

00:04:36.670 --> 00:04:38.240
on my vertical axis.

00:04:38.240 --> 00:04:40.060
And it's production possibilities curve,

00:04:40.060 --> 00:04:43.863
and so they typically
look something like this.

00:04:45.220 --> 00:04:49.560
Now they say indicate
a point on your graph,

00:04:49.560 --> 00:04:53.960
labeled Z, that reflects the
current level of unemployment.

00:04:53.960 --> 00:04:55.510
So this is very interesting.

00:04:55.510 --> 00:04:58.210
You might say hey it's
a point on my graph,

00:04:58.210 --> 00:05:01.910
maybe I need to put it
on this curve someplace.

00:05:01.910 --> 00:05:03.730
And that would not be the case here

00:05:03.730 --> 00:05:07.260
because we have some level
of cyclical unemployment.

00:05:07.260 --> 00:05:08.570
You see it right over here.

00:05:08.570 --> 00:05:12.869
Cyclical unemployment,
we are producing below

00:05:12.869 --> 00:05:16.610
our potential I guess is
one way you could say it.

00:05:16.610 --> 00:05:18.070
So that means we would be behind

00:05:18.070 --> 00:05:20.110
the production possibilities curve.

00:05:20.110 --> 00:05:22.960
So that point labeled Z,

00:05:22.960 --> 00:05:25.850
labeled Z, I'd put it
someplace behind the curve,

00:05:25.850 --> 00:05:28.496
and to get credit for this,
anywhere behind the curve

00:05:28.496 --> 00:05:31.050
would suffice, so you
could put it right there,

00:05:31.050 --> 00:05:32.370
our point Z.

00:05:32.370 --> 00:05:33.840
And since they're asking
us to show our work

00:05:33.840 --> 00:05:36.020
and it's always good to do things properly

00:05:36.020 --> 00:05:39.130
so if they're grading this
on an AP test for example,

00:05:39.130 --> 00:05:41.520
you would get points, it's
always good to put a title too.

00:05:41.520 --> 00:05:44.680
So you could say production
possibilities curve

00:05:44.680 --> 00:05:49.680
for Country, Country X, and we're done.


Identifying the constant of proportionality from equation

WEBVTT
Kind: captions
Language: en

00:00:00.180 --> 00:00:03.280
- [Instructor] When you hear
constant of proportionality,

00:00:03.280 --> 00:00:05.700
it can seem a little bit
intimidating at first.

00:00:05.700 --> 00:00:07.300
It seems very technical.

00:00:07.300 --> 00:00:10.720
But as we'll see, it's a
fairly intuitive concept,

00:00:10.720 --> 00:00:13.140
and we'll do several
examples and hopefully

00:00:13.140 --> 00:00:15.590
you'll get a lot more comfortable with it.

00:00:15.590 --> 00:00:18.350
So let's say we're trying to
make some type of baked goods,

00:00:18.350 --> 00:00:20.372
maybe it's some type of muffin,

00:00:20.372 --> 00:00:24.110
and we know that depending
on how many muffins

00:00:24.110 --> 00:00:25.350
we're trying to make,

00:00:25.350 --> 00:00:28.290
that for a given number of eggs,

00:00:28.290 --> 00:00:30.800
we always want twice as many cups of milk.

00:00:30.800 --> 00:00:35.560
So we could say cups of milk,

00:00:35.560 --> 00:00:38.490
cups of milk, that's going to be equal to

00:00:38.490 --> 00:00:43.490
two times the number of eggs.

00:00:43.780 --> 00:00:45.530
So what do you think the constant

00:00:45.530 --> 00:00:47.210
of proportionality is here,

00:00:47.210 --> 00:00:49.823
sometimes known as the
proportionality constant?

00:00:50.960 --> 00:00:54.010
Well yes, it is going to be two.

00:00:54.010 --> 00:00:55.980
This is a proportional relationship

00:00:55.980 --> 00:00:59.450
between the cups of milk
and the number of eggs.

00:00:59.450 --> 00:01:02.417
The cups of milk are always
going to be two times

00:01:02.417 --> 00:01:03.710
the number of eggs.

00:01:03.710 --> 00:01:05.850
Give me the number of eggs,
I'm going to multiply it

00:01:05.850 --> 00:01:09.520
by the constant of proportionality
to get the cups of milk.

00:01:09.520 --> 00:01:12.470
And we can see how this is
a proportional relationship

00:01:12.470 --> 00:01:14.480
a little bit clearer if we set up a table.

00:01:14.480 --> 00:01:16.940
So if we say number of eggs

00:01:17.810 --> 00:01:22.540
and if we say cups of milk

00:01:23.550 --> 00:01:25.203
and make a table here,

00:01:26.480 --> 00:01:29.110
well if you have one egg,
how many cups of milk

00:01:29.110 --> 00:01:30.100
are you gonna have?

00:01:30.100 --> 00:01:32.300
Well this right over here
would be one times two,

00:01:32.300 --> 00:01:34.220
well you're gonna have two cups of milk.

00:01:34.220 --> 00:01:36.970
If you had three eggs, well
you're just gonna multiply

00:01:36.970 --> 00:01:38.780
that by two to get your cups of milk,

00:01:38.780 --> 00:01:40.970
so you're gonna have six cups of milk.

00:01:40.970 --> 00:01:45.570
If you had 1,000,000 eggs, so
we have a very big party here,

00:01:45.570 --> 00:01:48.350
maybe we're some sort of
industrial muffin producer,

00:01:48.350 --> 00:01:49.640
well how many cups of milk?

00:01:49.640 --> 00:01:51.300
Well you put 1,000,000 in right over here,

00:01:51.300 --> 00:01:53.640
multiply it by two, you
get your cups of milk.

00:01:53.640 --> 00:01:57.330
You're going to need
2,000,000 cups of milk.

00:01:57.330 --> 00:02:00.410
And you can see that this is
a proportional relationship.

00:02:00.410 --> 00:02:02.450
To go from number of eggs to cups of milk,

00:02:02.450 --> 00:02:05.220
we indeed multiplied by two every time.

00:02:05.220 --> 00:02:07.680
That came straight from this equation.

00:02:07.680 --> 00:02:10.300
And you could also see,
look whenever you multiply

00:02:10.300 --> 00:02:11.670
your number of eggs by a certain amount,

00:02:11.670 --> 00:02:14.080
you're multiplying your cups
of milk by the same amount.

00:02:14.080 --> 00:02:16.380
If I multiply my eggs by 1,000,000,

00:02:16.380 --> 00:02:18.930
I'm multiplying my cups
of milk by 1,000,000.

00:02:18.930 --> 00:02:21.520
So this is clearly a
proportional relationship.

00:02:21.520 --> 00:02:23.820
Let's get a little bit
more practice identifying

00:02:23.820 --> 00:02:26.210
the constant of proportionality.

00:02:26.210 --> 00:02:28.580
So let's say I'll make it
a little bit more abstract,

00:02:28.580 --> 00:02:31.110
let's say I have some variable a

00:02:31.110 --> 00:02:36.110
and it is equal to five
times some variable b.

00:02:37.600 --> 00:02:39.680
What is the constant of
proportionality here?

00:02:39.680 --> 00:02:42.610
Pause this video and see
if you can figure it out.

00:02:42.610 --> 00:02:45.160
Yes, it is five.

00:02:45.160 --> 00:02:47.430
Give me a b, I'm gonna
multiply it by five,

00:02:47.430 --> 00:02:50.450
and I can figure out what a needs to be.

00:02:50.450 --> 00:02:52.220
Let's do another example.

00:02:52.220 --> 00:02:55.969
If I said that y is equal to

00:02:55.969 --> 00:03:00.969
pi times x, what is the constant
of proportionality here?

00:03:02.006 --> 00:03:05.470
Well you give me an x, I'm gonna
multiply it times a number,

00:03:05.470 --> 00:03:08.070
the number here is pi, to give you y.

00:03:08.070 --> 00:03:12.010
So our constant of
proportionality here is pi.

00:03:12.010 --> 00:03:13.170
Let's do one more.

00:03:13.170 --> 00:03:15.730
If I were to say

00:03:15.730 --> 00:03:20.730
that y is equal to 1/2 times x,

00:03:21.160 --> 00:03:22.830
what is the constant of proportionality?

00:03:22.830 --> 00:03:23.810
Pause this video.

00:03:23.810 --> 00:03:25.360
Think about it.

00:03:25.360 --> 00:03:27.440
Well once again, this is
just going to be the number

00:03:27.440 --> 00:03:29.920
that we're multiplying
by x to figure out y.

00:03:29.920 --> 00:03:33.070
So it is going to be 1/2.

00:03:33.070 --> 00:03:35.790
In general, you might sometimes
see it written like this.

00:03:35.790 --> 00:03:38.920
y is equal to k times x,

00:03:38.920 --> 00:03:41.770
where k would be some
constant that would be

00:03:41.770 --> 00:03:43.530
our constant of proportionality.

00:03:43.530 --> 00:03:46.300
You see 1/2 is equal to k here,

00:03:46.300 --> 00:03:48.950
pi is equal to k right over there.

00:03:48.950 --> 00:03:50.323
So hopefully that helps.


Impact of mass on orbital speed

WEBVTT
Kind: captions
Language: en

00:00:00.350 --> 00:00:01.690
- [Instructor] Let's
say that we've come up

00:00:01.690 --> 00:00:04.720
with a new pill that we
think has a good chance

00:00:04.720 --> 00:00:08.670
of helping people with diabetes
control their blood sugar.

00:00:08.670 --> 00:00:10.240
When someone has diabetes,

00:00:10.240 --> 00:00:11.850
their blood sugars unusually high,

00:00:11.850 --> 00:00:15.450
that damages their body in
a bunch of different ways.

00:00:15.450 --> 00:00:19.030
So we want to conduct
an experiment to test if

00:00:19.030 --> 00:00:22.670
this pill really can help
people lower their blood sugar.

00:00:22.670 --> 00:00:24.410
So the first thing we
need to think about is

00:00:24.410 --> 00:00:26.480
how do we even measure or test

00:00:26.480 --> 00:00:29.400
whether peoples' blood
sugar is getting lower.

00:00:29.400 --> 00:00:31.690
Well, for our experiment,
what's typically done

00:00:31.690 --> 00:00:35.023
is we measure folks hemoglobin A1C.

00:00:36.170 --> 00:00:37.350
You don't have to worry too much

00:00:37.350 --> 00:00:40.090
about this in the context of statistics.

00:00:40.090 --> 00:00:42.100
But hemoglobin A1C test is a way

00:00:42.100 --> 00:00:44.120
that's typically used to measure

00:00:44.120 --> 00:00:46.900
your average blood sugar
over the last three months,

00:00:46.900 --> 00:00:48.710
and we have whole videos on Khan Academy

00:00:48.710 --> 00:00:51.050
explaining how that works.

00:00:51.050 --> 00:00:54.060
So our hope would be that
our pill lowers peoples'

00:00:54.060 --> 00:00:57.680
blood sugar which shows
up as a lowered A1C.

00:00:57.680 --> 00:01:00.000
Now we have terms for this.

00:01:00.000 --> 00:01:03.990
The thing that is causing
something else to change,

00:01:03.990 --> 00:01:07.150
we call this the explanatory variable.

00:01:07.150 --> 00:01:10.740
Explanatory variable,

00:01:10.740 --> 00:01:13.250
and the thing that might get changed

00:01:13.250 --> 00:01:14.990
by that explanatory variable, depending

00:01:14.990 --> 00:01:16.450
on whether you take the pill or not,

00:01:16.450 --> 00:01:19.083
we call that our response.

00:01:19.950 --> 00:01:22.060
Response variable.

00:01:22.060 --> 00:01:25.090
So now let's actually
conduct the experiment.

00:01:25.090 --> 00:01:26.248
So what we would do is

00:01:26.248 --> 00:01:28.933
we would go to the population.

00:01:29.790 --> 00:01:34.750
Population of diabetics,

00:01:34.750 --> 00:01:37.710
and we would want to take a random sample

00:01:37.710 --> 00:01:40.800
from that population of diabetics.

00:01:40.800 --> 00:01:43.250
A reasonably large one,
and later in statistics

00:01:43.250 --> 00:01:46.370
we talk about what a good
size sample might be.

00:01:46.370 --> 00:01:48.990
But let's say that we randomly sample.

00:01:48.990 --> 00:01:51.790
Randomly sample

00:01:53.050 --> 00:01:54.710
100 folks.

00:01:54.710 --> 00:01:57.640
So we randomly sample 100 folks

00:01:57.640 --> 00:02:01.290
from that population of diabetics,

00:02:01.290 --> 00:02:03.700
and then you would want to assign

00:02:03.700 --> 00:02:07.310
these folks randomly to
two different groups.

00:02:07.310 --> 00:02:09.880
One would be your control group,

00:02:09.880 --> 00:02:11.580
and this would be the group of people

00:02:11.580 --> 00:02:13.350
who won't take the new medicine,

00:02:13.350 --> 00:02:16.090
and then you would have
your treatment group.

00:02:16.090 --> 00:02:17.410
These are the groups of folks

00:02:17.410 --> 00:02:20.150
who will be given the new medicine.

00:02:20.150 --> 00:02:22.220
The treatment group.

00:02:22.220 --> 00:02:24.710
Now in some cases, you
can just randomly assign

00:02:24.710 --> 00:02:27.260
these 100 folks between these two groups,

00:02:27.260 --> 00:02:28.850
and one way to do it is you could give all

00:02:28.850 --> 00:02:31.560
of them a random number
between one and 100

00:02:31.560 --> 00:02:33.390
and then the top 50 go into treatment

00:02:33.390 --> 00:02:34.910
and the bottom 50 go into the control,

00:02:34.910 --> 00:02:38.400
or there's, you can use a
computer to randomly assign folks.

00:02:38.400 --> 00:02:39.700
Now sometimes you might want to be

00:02:39.700 --> 00:02:41.970
a little bit more sophisticated than that.

00:02:41.970 --> 00:02:45.010
For example, there might be
evidence that someone's sex

00:02:45.010 --> 00:02:48.730
might somehow influence
how they respond to a drug.

00:02:48.730 --> 00:02:52.020
So what you could do is
something called block design

00:02:52.020 --> 00:02:54.130
where, let's say, this group just happens

00:02:54.130 --> 00:02:58.970
to have 60 females and 40 males.

00:02:58.970 --> 00:03:00.483
One block design.

00:03:01.360 --> 00:03:04.740
You can randomly assign,
but you can do it in a way

00:03:04.740 --> 00:03:07.350
that you can ensure that
both of these groups

00:03:07.350 --> 00:03:10.110
have the same proportions
of male and females.

00:03:10.110 --> 00:03:12.470
So for example, if you
have 60 females here,

00:03:12.470 --> 00:03:15.500
you can ensure that 30 of
them end up in the control,

00:03:15.500 --> 00:03:17.330
and 30 end up in the treatment.

00:03:17.330 --> 00:03:21.190
But you would assign those,
those 60 females randomly

00:03:21.190 --> 00:03:22.380
between these two groups,

00:03:22.380 --> 00:03:24.990
and similarly, you can do block design

00:03:24.990 --> 00:03:27.820
of these 40 males, 20
end up in the control,

00:03:27.820 --> 00:03:30.250
and 20 end up in the treatment.

00:03:30.250 --> 00:03:33.130
So once you have folks
in both of these groups,

00:03:33.130 --> 00:03:35.030
what you would probably want to do

00:03:35.030 --> 00:03:38.670
is measure their A1C at the beginning.

00:03:38.670 --> 00:03:40.840
You can view that as a baseline,

00:03:40.840 --> 00:03:44.030
and then, over the
course of the experiment,

00:03:44.030 --> 00:03:48.030
you would give the pill
to the treatment group,

00:03:48.030 --> 00:03:50.210
and in the control group,
you might be saying,

00:03:50.210 --> 00:03:51.920
well, we would just wouldn't do anything.

00:03:51.920 --> 00:03:55.150
But the best practice is
actually to give a pill

00:03:55.150 --> 00:03:58.870
that looks just like the real
thing to the control group.

00:03:58.870 --> 00:04:01.930
This is known as a placebo,

00:04:01.930 --> 00:04:04.000
and the reason why we do that

00:04:04.000 --> 00:04:07.930
is there's definitely evidence
that when people think

00:04:07.930 --> 00:04:10.380
they are taking a pill
that might help them,

00:04:10.380 --> 00:04:12.940
that even psychologically it
can have an effect on them,

00:04:12.940 --> 00:04:14.470
and sometimes it helps them.

00:04:14.470 --> 00:04:16.800
This is known as the placebo effect,

00:04:16.800 --> 00:04:19.030
and not only would you give both groups

00:04:19.030 --> 00:04:20.520
a pill that looks the same,

00:04:20.520 --> 00:04:22.520
even though this one
in the treatment group

00:04:22.520 --> 00:04:25.110
actually has the medicine
in it, you also would

00:04:25.110 --> 00:04:28.610
not want to tell folks
which group they are in.

00:04:28.610 --> 00:04:30.840
When you don't tell them
which group they're in,

00:04:30.840 --> 00:04:34.420
that's known as a blind experiment,

00:04:34.420 --> 00:04:37.110
and you probably also don't
want to tell the people

00:04:37.110 --> 00:04:39.030
who are administering the
experiment which group

00:04:39.030 --> 00:04:42.310
they are administering, and
that's called a double blind.

00:04:42.310 --> 00:04:44.790
So even the doctors or the nurses

00:04:44.790 --> 00:04:46.200
that are administering the experiment,

00:04:46.200 --> 00:04:47.800
when they're giving a
pill to the control group,

00:04:47.800 --> 00:04:50.480
they don't know that
that pill is the placebo,

00:04:50.480 --> 00:04:52.107
and you might say, well,
why is it important

00:04:52.107 --> 00:04:54.500
for an experiment to be blind,

00:04:54.500 --> 00:04:56.350
or especially double blind.

00:04:56.350 --> 00:04:59.390
Well, that avoids, one, any
type of psychological effect

00:04:59.390 --> 00:05:01.290
on the, from the point of the patient.

00:05:01.290 --> 00:05:04.150
Or from the, say the
caregivers in this situation,

00:05:04.150 --> 00:05:05.650
so that they don't kind of give it away.

00:05:05.650 --> 00:05:06.680
They don't tell these folks,

00:05:06.680 --> 00:05:09.270
hey, you're actually just
pretending to take a pill,

00:05:09.270 --> 00:05:12.600
and so that ensures that
we minimize the amount

00:05:12.600 --> 00:05:14.940
of influence or bias that might happen.

00:05:14.940 --> 00:05:17.020
You might even have a
triple blind experiment

00:05:17.020 --> 00:05:20.190
where even the folks who are
analyzing the eventual data

00:05:20.190 --> 00:05:22.420
from this experiment don't
know whether they're analyzing

00:05:22.420 --> 00:05:24.310
the data from the
control or the treatment.

00:05:24.310 --> 00:05:26.640
They just compare the
two different groups.

00:05:26.640 --> 00:05:30.520
But anyway, you do, you
people take the medicine

00:05:30.520 --> 00:05:32.640
and the placebo over the
course of the experiment.

00:05:32.640 --> 00:05:34.620
Maybe this lasts for three months,

00:05:34.620 --> 00:05:37.900
and then you would want to
measure their A1C later,

00:05:37.900 --> 00:05:42.330
and then you would see
their change in the A1C.

00:05:42.330 --> 00:05:44.340
Now if you saw that there
wasn't really a difference

00:05:44.340 --> 00:05:46.620
in the change in A1C between the control

00:05:46.620 --> 00:05:48.390
and the treatment group, then you'd say,

00:05:48.390 --> 00:05:52.410
well, that probably means
that my pill didn't work.

00:05:52.410 --> 00:05:54.520
Now if you do get a greater reduction in

00:05:54.520 --> 00:05:56.750
the treatment group, and you
do the statistical analysis

00:05:56.750 --> 00:05:58.210
which we will learn in statistics

00:05:58.210 --> 00:06:00.820
and you show that, hey,
there's a very low probability

00:06:00.820 --> 00:06:03.230
that's happened purely due to chance.

00:06:03.230 --> 00:06:04.480
Well then, you've got something.

00:06:04.480 --> 00:06:06.940
You could probably conclude that

00:06:06.940 --> 00:06:08.860
there is a causal connection between

00:06:08.860 --> 00:06:12.560
taking the pill and
lowering your A1C level.

00:06:12.560 --> 00:06:16.110
But once again, you cannot be 100% sure,

00:06:16.110 --> 00:06:18.913
and so, this is why it's very important

00:06:18.913 --> 00:06:23.083
for people to be able to
replicate your experiment.

00:06:24.000 --> 00:06:25.990
Because what you'd want
to do either yourself

00:06:25.990 --> 00:06:28.300
or other researchers might want to conduct

00:06:28.300 --> 00:06:30.240
the experiment with different sample sizes

00:06:30.240 --> 00:06:32.460
and different countries
and different populations,

00:06:32.460 --> 00:06:35.140
maybe with different ages
at different times of year

00:06:35.140 --> 00:06:38.763
to ensure that they
continue to see this result.


Can causality be established from this study?

WEBVTT
Kind: captions
Language: en

00:00:00.700 --> 00:00:02.730
- [Instructor] A gym that
specializes in weight loss

00:00:02.730 --> 00:00:05.090
offers its members an optional dietary

00:00:05.090 --> 00:00:07.130
program for an extra fee.

00:00:07.130 --> 00:00:10.420
To study the effectiveness
of the dietary program,

00:00:10.420 --> 00:00:13.900
a manager at the gym takes a
random sample of 50 members

00:00:13.900 --> 00:00:16.080
who participate in the dietary program

00:00:16.080 --> 00:00:18.150
and 50 members who don't.

00:00:18.150 --> 00:00:20.500
The manager finds that
those who participated

00:00:20.500 --> 00:00:23.070
in the dietary program, on average,

00:00:23.070 --> 00:00:24.730
lost significantly more weight

00:00:24.730 --> 00:00:26.270
than those who didn't participate

00:00:26.270 --> 00:00:29.030
in the program in the past three months.

00:00:29.030 --> 00:00:31.480
The manager concludes
that the dietary program

00:00:31.480 --> 00:00:33.810
caused the increased weight loss

00:00:33.810 --> 00:00:37.380
for the gym members
during that time period.

00:00:37.380 --> 00:00:40.410
So pause this video, and
see, and think about whether

00:00:40.410 --> 00:00:43.450
you think the manager is
making a valid conclusion

00:00:43.450 --> 00:00:45.453
based on this study.

00:00:46.610 --> 00:00:48.580
Alright, so let's first
just make sure we understand

00:00:48.580 --> 00:00:50.410
what the manager is concluding.

00:00:50.410 --> 00:00:53.190
The manager is saying that
there is a causal relationship

00:00:53.190 --> 00:00:54.590
between the dietary program,

00:00:54.590 --> 00:00:56.420
that being on the dietary program

00:00:56.420 --> 00:01:01.420
causes increased weight loss.

00:01:01.920 --> 00:01:04.290
And they would be able
to make this conclusion

00:01:04.290 --> 00:01:07.360
if it's a well designed
experimental study.

00:01:07.360 --> 00:01:08.450
And you might say, well what does

00:01:08.450 --> 00:01:10.290
an experimental study look like?

00:01:10.290 --> 00:01:13.400
Well in an experimental study
you have a control group

00:01:13.400 --> 00:01:15.280
that wouldn't have the dietary program,

00:01:15.280 --> 00:01:18.690
and then you would have a
treatment or experimental group

00:01:18.690 --> 00:01:21.370
that does have the dietary program.

00:01:21.370 --> 00:01:23.660
And then you would see, hey if these folks

00:01:23.660 --> 00:01:25.600
are actually seeing more weight loss,

00:01:25.600 --> 00:01:27.330
and if it's statistically significant

00:01:27.330 --> 00:01:29.730
then maybe you can conclude
the causal relationship

00:01:29.730 --> 00:01:32.250
that the dietary program
is causing the weight loss.

00:01:32.250 --> 00:01:35.680
And this kind of looks like
that, until you think about

00:01:35.680 --> 00:01:38.640
how folks were assigned
to either of these groups.

00:01:38.640 --> 00:01:41.350
It would be a well
designed experimental study

00:01:41.350 --> 00:01:45.460
if you took random samples
from the broader population,

00:01:45.460 --> 00:01:48.490
so you took a random sample,
so that's our random sample

00:01:48.490 --> 00:01:49.920
from the broader population.

00:01:49.920 --> 00:01:54.190
And then from this group
you randomly assigned folks

00:01:54.190 --> 00:01:56.340
to either the control or the treatment.

00:01:56.340 --> 00:01:59.520
So you're randomly assigning,
and then the people

00:01:59.520 --> 00:02:01.270
who happened to be in the treatment group,

00:02:01.270 --> 00:02:03.490
not the people who chose to be in it.

00:02:03.490 --> 00:02:06.910
Well those people, you'd say,
you need to be on this diet

00:02:06.910 --> 00:02:08.790
and you make sure that
they are on that diet.

00:02:08.790 --> 00:02:11.900
And then if you see a
statistically significant

00:02:11.900 --> 00:02:13.490
increased weight loss then you might

00:02:13.490 --> 00:02:15.180
be able to make this conclusion.

00:02:15.180 --> 00:02:17.490
But that's not what happened over here.

00:02:17.490 --> 00:02:22.400
In this situation, we
didn't randomly select

00:02:22.400 --> 00:02:24.900
from the broader population
and then randomly assign

00:02:24.900 --> 00:02:26.570
folks to these groups.

00:02:26.570 --> 00:02:30.490
What happened is people
self selected into either

00:02:30.490 --> 00:02:32.630
being in the dietary program,

00:02:32.630 --> 00:02:34.700
or not being in the dietary program.

00:02:34.700 --> 00:02:38.090
I'll say, not the dietary program.

00:02:38.090 --> 00:02:41.960
And then what they did is
that they randomly sampled

00:02:41.960 --> 00:02:43.970
from the dietary program to put them in,

00:02:43.970 --> 00:02:46.510
I guess you could say the treatment group

00:02:46.510 --> 00:02:49.810
and then they randomly sampled
from this control group.

00:02:49.810 --> 00:02:52.370
And so in this situation
you have a significant

00:02:52.370 --> 00:02:56.210
confounding variable, people
essentially self selected

00:02:56.210 --> 00:02:59.600
themselves into the dietary program group.

00:02:59.600 --> 00:03:02.680
And that you could view
as a confounding variable,

00:03:02.680 --> 00:03:06.040
and so it doesn't allow you
to make this causal connection

00:03:06.040 --> 00:03:08.460
because people who selected themselves

00:03:08.460 --> 00:03:10.220
into the dietary program,

00:03:10.220 --> 00:03:12.110
maybe they're more
motivated to lose weight.

00:03:12.110 --> 00:03:15.770
Maybe they can afford the money
and that wealth association

00:03:15.770 --> 00:03:17.740
is associated with being
able to eat better,

00:03:17.740 --> 00:03:19.920
and maybe being able to lose more weight.

00:03:19.920 --> 00:03:22.620
Now a conclusion that the
manager might be able to make

00:03:22.620 --> 00:03:25.440
based on this study is that
there is an association

00:03:25.440 --> 00:03:29.000
between participating
in the dietary program

00:03:29.000 --> 00:03:31.210
and weight loss, but once again

00:03:31.210 --> 00:03:33.153
you can't establish the causality.