A growing literature establishes that high quality early childhood interventions targeted toward disadvantaged children have substantial impacts on later life outcomes. Little is known about the mechanisms producing these impacts. This paper uses longitudinal data on cognitive and personality...

We find large effects on the earnings of participants from a randomized intervention that gave psychosocial stimulation to stunted Jamaican toddlers living in poverty. The intervention consisted of one-hour weekly visits from community Jamaican health workers over a 2-year period that taught...

This paper demonstrates that even under ideal conditions, social experiments in general only uniquely determine the mean impacts of programs but not the median or the distribution of program impacts. The conventional common parameter evaluation model widely used in econometrics is one case where...

This paper decomposes the participation process of a prototypical program into eligibility, awareness, application, acceptance and enrollment. With this decomposition, we determine the sources of unequal participation for different groups, and demonstrate that variables often have very different...

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....