"Evaluating Contradictory Experimental and Non-Experimental Estimates of Neighborhood Effects on Economic Outcomes for Adults"
Duncan researches the roles that families, peers, neighborhoods and public policy play in affecting the life chances of children and adolescents. Currently, he is part of a team conducting a random-assignment trial assessing impacts of income supplements on the cognitive development of infants born to poor mothers in four diverse U.S. communities. Duncan is a member of the National Academy of Arts and Sciences and the National Academy of Sciences, and the Kenneth Boulding Fellow of the American Academy of Political and Social Science. He has served as president of the Population Association of America and the Society for Research in Child Development. Among his many honors are the Klaus J. Jacobs Research Prize and the Society for Research in Child Development Award for Distinguished Contributions to Public Policy and Practice in Child Development.
Although non-experimental studies find robust neighborhood effects on adults, such findings have been challenged by results from the Moving to Opportunity (MTO) residential mobility experiment. Using a within-study comparison design, this paper compares experimental and non-experimental estimates from MTO and a parallel analysis of the Panel Study of Income Dynamics (PSID). Striking similarities were found between non-experimental estimates based on MTO and PSID. No clear evidence was found that different estimates are related to duration of adult exposure to disadvantaged neighborhoods, non-linear effects of neighborhood conditions, magnitude of the change in neighborhood context, frequency of moves, treatment effect heterogeneity, or measurement, although uncertainty bands around our estimates were sometimes large. One other possibility is that MTO-induced moves might have been unusually disruptive, but results are inconsistent for that hypothesis. Taken together, the findings suggest that selection bias might account for evidence of neighborhood effects on adult economic outcomes in non-experimental studies.