A randomized experiment that measures the impact of a social policy in a sample of the population reveals whether the policy will work on average with universal application. An experiment that includes only the subset of the population that volunteers for the intervention generates narrower "proof-of-concept" evidence of whether the…

Research questions regarding how, for whom, and where a treatment achieves its effect on an outcome have become increasingly valued in substantive research. Such questions can be answered by causal moderated mediation analysis, which assesses the heterogeneity of the mediation mechanism underlying the treatment effect across individual and…

The Upward Bound Math and Science (UBMS) program at Temple University (TU) seeks to guide first-generation, low-income high school students from Philadelphia in their quest to obtain postsecondary STEM degrees that lead to related careers. This study aims to evaluate the efficacy of the program by analyzing its students' performance in light of…

Head Start is a national program that helps young children from families with low incomes get ready to succeed in school. It does this by working to promote their early learning and health and their families' well-being. The Head Start Family and Child Experiences Survey (FACES) provides national information about Head Start programs and…

Panel or grouped data are often used to allow for unobserved individual heterogeneity in econometric models via fixed effects. In this paper, we discuss identification of a panel data model in which the unobserved heterogeneity both enters additively and interacts with treatment variables. We present identification and estimation methods for…

This technical supplement to the Supplemental Nutrition Assistance Program (SNAP) Employment and Training (E&T) evaluation final reports presents details of the technical approach used for creating analysis variables and estimating impacts of treatment group services on outcomes, including employment, earnings, and SNAP participation. It also…