+--------+-------------------+
| Airq   | R Documentation   |
+--------+-------------------+

Air Quality for Californian Metropolitan Areas
----------------------------------------------

Description
~~~~~~~~~~~

a cross-section from 1972

*number of observations* : 30

*observation* : regional

*country* : United States

Usage
~~~~~

::

    data(Airq)

Format
~~~~~~

A dataframe containing :

airq
    indicator of air quality (the lower the better)

vala
    value added of companies (in thousands of dollars)

rain
    amount of rain (in inches)

coas
    is it a coastal area ?

dens
    population density (per square mile)

medi
    average income per head (in US dollars)

References
~~~~~~~~~~

Verbeek, Marno (2004) *A guide to modern econometrics*, John Wiley and
Sons,
`http://www.econ.kuleuven.ac.be/GME <http://www.econ.kuleuven.ac.be/GME>`_,
chapter 4.

See Also
~~~~~~~~

``Index.Source``, ``Index.Economics``, ``Index.Econometrics``,
``Index.Observations``
