This paper considers the problem of policy evaluation in a modern society with heterogeneous agents and diverse groups with conflicting interests. Several different approaches to the policy evaluation problem are compared including the approach adopted in modern welfare economics, the classical...

The recent experimental evaluation of the U.S. Job Training Partnership Act (JTPA) program found negative effects of training on the earnings of disadvantaged male youth and no effect on the earnings of disadvantaged female youth. These findings provided justification for Congress to cut the...

This paper considers the use of instrumental variables to estimate the mean effect of treatment on the treated. It reviews previous work on this topic by Heckman and Robb (1985, 1986) and demonstrates that (a) unless the effect of treatment is the same for everyone (conditional on observables),...

This paper considers the recent case for randomized social experimentation and contrasts it with older cases for social experimentation. The recent case eschews behavioral models, assumes that certain mean differences in outcomes are the parameters of interest to evaluators and assumes that...

The recent literature on evaluating manpower training programs demonstrates that alternative nonexperimental estimators of the same program produce a array of estimates of program impact. These findings have led to the call for experiments to be used to perform credible program evaluations....

In recent years, the study of labor supply has occupied the attention of a large number of economists. With the growth in interest in the topic and with the inevitable diversity of economic models and statistical methods proposed by new entrants in the field, the literature has developed its own...

We report the labor market effects of the Jamaica Early Childhood Stimulation intervention at age 31. The study is a small-sample randomized early childhood education stimulation intervention targeting stunted children living in the poor neighborhoods of Kingston, Jamaica. Implemented in...

This paper compares the structural approach to economic policy analysis with the program evaluation approach. It offers a third way to do policy analysis that combines the best features of both approaches. We illustrate the value of this alternative approach by making the implicit economics of...

This paper estimates the rate of return to the High/Scope Perry Preschool Program, an early intervention program targeted toward disadvantaged African-American youth. Estimates of the rate of return to the Perry program are widely cited to support the claim of substantial economic benefits from...

This paper develops methods for evaluating marginal policy changes. We characterize how the effects of marginal policy changes depend on the direction of the policy change, and show that marginal policy effects are fundamentally easier to identify and to estimate than conventional treatment...