The life cycle of money
I'll answer but avoiding discussion of M1, M2 etc, too pedantic. I don't believe you are asking about the lifetime of either coins or paper money. I think you are referencing the fractional reserve system, and how a good portion of the total money supply is created by the banks lending out their deposits in effect 'creating' money. My answer to you is that if all loans were simply paid off, no mortgages, no car loans, etc, the total money in the system would collapse to some reasonable fraction of what it is today, 10% or a bit less. This comes from the fact that the reserve requirement for most large banks is 10%.  I'm referencing money, but not bills or coins. Think about what you make in a year. How much do you touch as paper money? For my wife and me, it's no more than a few percent. Most goes from a direct deposit to online payments. So this would be the subject of a different question altogether.  Let me know if this addresses your question. Echoing JohnF, and assuming you mean the physical, rather than abstract meaning of money?  The abstract concept obviously isn't replaced (unless the currency is discredited, or like the creation of the Euro which saw local currencies abandoned). The actual bits of paper are regularly collected, shredded (into itty-bitty-bits) and destroyed.  Coinage tends to last a lot longer, but it also collected and melted down eventually. Depends on the country, though.  No doubt, many people who took a gap year to go travelling in points diverse came across countries where the money is a sort of brown-grey smudge you hold with care in thick wadges. The more modern economies replace paper money on a dedicated cycle (around three years according to Wikipedia, anyway).
Yet *another* redistributionist jew? (Michael Kinsley)  He wants us to believe that what was earned through voluntary transactions with other people somehow should be taken by another organization of people called the federal government, so his friends and fellow jewish redistributionists can plunder on an even more massive scale.  Money received through voluntary transactions belong to the owner. Period. This jew Kinsley wants us to form a mob and steal to give his jewish friends in govt have more money to spend. Period. What do you call a woman's monthly cycle? Period. "Remember that ""earned"" means ""earned in profit."" A company like LinkedIn may not be trying to earn any profit, because they believe that they are at the stage in their development where the best thing to do with excess cash is to reinvest it in growing the business. Therefore, profit may not be the best metric at this stage in the company's life cycle." Capital circulation doesn't work in the model of everyone producing products they can all already produce independently, and the money going to raw material and 3D printer inputs are a fixed cost to all construction, which outside of asteroid mining has limitations.    The Economy needs a stable cycle for capital, the challenge with this automation is that the requirement for capital circulation appears vulnerable to instability. Remove your money.  If you do not need this money for some time, you can convert it to Gold, and now is a good time to buy.  Gold is not expected to decrease much in price as we're already at the bottom of the employment cycle and the Depression is already begun and will take about two years to grip the world. What you are seeing is the effects of inflation. As money becomes less valuable it takes more of it to buy physical things, be they commodities, shares in a company's stock, and peoples time (salaries).  Just about the only thing that doesn't track inflation to some degree is cash itself or money in an account since that is itself what is being devalued.  So the point of all this is, buying anything (a house, gold, stocks) that doesn't depreciate (a car) is something of a hedge against inflation. However, don't be tricked (as many are) into thinking that house just made you a tidy sum just because it went up in value so much over x years. Remember 1) All the other houses and things you'd spend the money on are a lot more expensive now too; and 2) You put a lot more money into a house than the mortgage payment (taxes, insurance, maintenance, etc.) I'm with the others though. Don't get caught up in the gold bubble. Doing so now is just speculation and has a lot of risk associated with it. "Wow, this turns out to be a much more difficult problem than I thought from first looking at it. Let's recast some of the variables to simplify the equations a bit. Let rb be the growth rate of money in your bank for one period. By ""growth rate"" I mean the amount you will have after one period. So if the interest rate is 3% per year paid monthly, then the interest for one month is 3/12 of 1% = .25%, so after one month you have 1.0025 times as much money as you started with. Similarly, let si be the growth rate of the investment. Then after you make a deposit the amount you have in the bank is pb = s. After another deposit you've collected interest on the first, so you have pb = s * rb + s. That is, the first deposit with one period's growth plus the second deposit. One more deposit and you have pb = ((s * rb) + s) * rb + s = s + s * rb + s * rb^2. Etc. So after n deposits you have pb = s + s * rb + s * rb^2 + s * rb^3 + ... + s * rb^(n-1). This simplifies to pb = s * (rb^n - 1)/(rb - 1). Similarly for the amount you would get by depositing to the investment, let's call that pi, except you must also subtract the amount of the broker fee, b. So you want to make deposits when pb>pi, or s*(ri^n-1)/(ri-1) - b > s*(rb^n-1)/(rb-1) Then just solve for n and you're done! Except ... maybe someone who's better at algebra than me could solve that for n, but I don't see how to do it. Further complicating this is that banks normally pay interest monthly, while stocks go up or down every day. If a calculation said to withdraw after 3.9 months, it might really be better to wait for 4.0 months to collect one additional month's interest. But let's see if we can approximate. If the growth rates and the number of periods are relatively small, the compounding of growth should also be relatively small. So an approximate solution would be when the difference between the interest rates, times the amount of each deposit, summed over the number of deposits, is greater than the fee. That is, say the investment pays 10% per month more than your bank account (wildly optimistic but just for example), the broker fee is $10, and the amount of each deposit is $200. Then if you delay making the investment by one month you're losing  10% of $200 = $20. This is more than the broker fee, so you should invest immediately. Okay, suppose more realistically that the investment pays 1% more per month than the bank account. Then the first month you're losing 1% of $200 = $2. The second month you have $400 in the bank, so you're losing $4, total loss for two months = $6. The third month you have $600 in the bank so you lose an additional $6, total loss = $12. Etc. So you should transfer the money to the investment about the third month. Compounding would mean that losses on transferring to the investment are a little higher than this, so you'd want to bias to transferring a little earlier. Or, you could set up a spreadsheet to do the compounding calculations month by month, and then just look down the column for when the investment total minus the bank total is greater than the broker fee. Sorry I'm not giving you a definitive answer, but maybe this helps." seriously money is debt has to be the most ridiculous comparison i've ever heard. that statement implies commutativity and certainly i would never say debt is money. i could take on debt to get money, but the debt itself is a liability and not an asset.  your last paragraph about fiat money is correct, but i should say that with modern financial markets price discovery isn't some magic voodoo thing. "Here's some way of thinking about it, and I'm not really sure if it's completely correct, but sometimes we oversimplify when trying to tell a five year old :)  Say there are two people in the world. You and me. We both have $100. A total of $200 in the world.  Suddenly, a wild bank appears. I deposit my $100 in the bank. I still have $100 and you still have $100. Now you want to buy something from me that costs $150. You go to the bank to loan money. The bank has $100 available so gives you $50. You give me $150. Now I have $250 and you are $50 in debt. I deposit the $150 in the bank.  We do this again and again, until I have $1000 on my bank account, and you are $900 in debt. I want to buy a house of $500 and go to my bank, demanding to take out $500. But there is only $200 in the whole world so the bank can only give me $200.  ""Money"" has been created out of thin air, but it's actually you who are in debt. If you go bankrupt, the bank has a big debt it won't get back, and is in deep shit when I come around to demand my money back. At that point governments step in to loan the bank money for cheap, because if the bank fails, I will lose all my pension savings I put into that bank, as well as my companies and a lot of my employees.  And other banks loaned this bank money, so if this bank fails, the other banks will be in the exact same position and will also fail, because then they will also have debts that won't be paid back.  There are regulations minimizing this - i.e. a bank is required to keep a percentage of the amount of money on its accounts, so there's a maximum limit of ""money created""."