Results reported in this paper indicate that the returns-to-schooling
profile exhibits a peculiar departure from log-linearity. In
particular, for white males, the return to the 15th year of schooling
(the third year of college) seems to be much smaller than that predicted
by log-linearity. That is, people with 15 years of schooling do not
appear to earn any more than those with 14 years of schooling. I
discuss several theories and evidence that may explain the peculiarity.
Amongst them, measurement error in schooling seems the most plausible.

This paper summarizes the literature on the impact of employment
and training programs and concludes that they have been neither an
overwhelming success nor a complete failure in terms of their ability to
increase the long-term employment and earnings of disadvantaged workers.
Employment and earnings programs capacity to improve the lot of any
given participant, and the collective economic well—being of the disad-
vantaged, has been modest —— as has been the level of resources devoted
to these programs.
Two decades of non-experimental program evaluation in the
employment and training field have finally taught a less about which
there can be little disagreement: Convincing program evaluation is
going to require continued use of randomized trials. We wish to
emphasize that this is not simply a statement that randomization is a
preferable methodological approach regardless of the field of study.
Instead, we believe the evidence in the study of employment and training
programs overwhelmingly indicates that randomization is essential in
program evaluation in the employment and training field. The difficulty
seems to be that the earnings determination processes of today's workers
and the program selection methods of today's programs interact to make
it nearly impossible to produce reliable estimates of how workers ear-
nings would have behaved in the absence of a program. The evidence to
support this finding comes from both experimental and non—experimental
studies. The non-experimental studies indicate that minor changes in
methods, for which there is no empirical justification, produce large
swings in estimated program effects. The study of experimental findings
indicates that perfectly plausible non—experimental methods may lead to
dramatic errors in inferences about program effects.
This basic finding raises a fundamental question: What is the
proper reaction of policy makers? In our view the appropriate reaction
is for policymakers to begin the development of a credible research and
development effort using randomized clinical trials in a wide variety of
study areas.

While policymakers often promote further education for displaced workers, evidence on its effectiveness in the U.S. context primarily comes from evaluations of specific government sponsored training programs, which only represent one narrow avenue for skill acquisition. This paper studies the returns to retraining among unemployed workers, where retraining is broadly defined as enrollment in community colleges, four-year institutions, and technical centers. We link together high quality administrative records from the state of Ohio and estimate the returns using a matching design in which we compare the labor market outcomes of similar workers who do and do not enroll. Our matching specification is informed by a separate validation exercise in the spirit of LaLonde (1986), which evaluates a wide array of estimators using a combination of experimental and non-experimental data in a setting similar to ours. We graphically present the average quarterly earnings trajectories of the enrollees and matched non-enrollees over a nine-year period and show that there is little difference in earnings pre-enrollment, followed by temporarily depressed earnings among enrollees during the first two years after enrolling, and sustained positive returns thereafter. We find that enrollees experience an average earnings gain of seven percent three to four years after enrolling, and that the returns are driven by those who switch industries, particularly to healthcare.