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James Heckman (born April 19, 1944) is an
economist at the University of Chicago. He was the
winner of The Bank of Sweden Prize in Economic
Sciences in Memory of Alfred Nobel in 2000 for his
pioneering work in econometrics and
microeconomics.  

Heckman began his career at Colorado College.
Heckman then received his Doctor of
Philosophy|Ph.D. in economics from Princeton
University in 1971, and served as an Assistant
Professor at Columbia University before going to
the University of Chicago.

Heckman is most famous for introducing the concept
of "selection bias" into modern econometrics.  The
literature has always been complex, but the main
idea is fairly simple.  Economists routinely take
data on wages to calculate average wages.  Many
subjects are unemployment|unemployed, and thus
would have missing wages.  Before Heckman,
economists would simply discard all records with
missing wages and then calculate averages using
the remaining observations.  Heckman shows that
this process can lead to selection bias because
observations do not have missing wages at random. 
For instance, poorer individuals of one group may
be unemployed more often, so average wages may be
too high for this group.  Thus, Heckman's work has
persuaded economists to treat missing observations
more carefully. He has also pioneered the
application of economics to econometrics and has
conducted numerous empirical studies.

==See also==

*List of economists
*List of economics consultancies and think tanks