Labor Studies.

• Position: Program and Working Group Meetings - National Bureau of Economic Research

NBER's Labor Studies Program met in Cambridge on April 6. Program Director Richard B. Freeman and NBER Research Associate Lawrence F. Katz organized the meeting. These papers were discussed:

Alberto Abadie, Harvard University and NBER; and Alexis Diamond and Jen Hainmueller, Harvard University, "Synthetic Control Methods for Comparative Case Studies: Estimating the Effects of California's Tobacco Control Program" (NBER Working Paper No. 12831)

Timothy G. Conley, University of Chicago, and Christopher R. Taber, Northwestern University and NBER, "Inference with 'Differences in Differences' with a Small Number of Policy Changes"

Muriel Niederle, Stanford University and NBER; Carmit Segal, Harvard University; and Lise Vesterlund, University of Pittsburgh, "How Costly is Diversity? Affirmative Action in Competitive Environments"

Stefano DellaVigna, University of California, Berkeley and NBER, and Eliana La Ferrara, Universita Bocconi and IGIER, "Detecting Illegal Arms Trade"

Bruce D. Meyer, University of Chicago and NBER, and Wallace K.C. Mok, Northwestern University of Notre Dame, "Quasi-Experimental Evidence on the Effects of Unemployment Insurance from New York State"(NBER Working Paper No. 12865)

Michael W. Elsby and Gary Solon, University of Michigan and NBER, and Ryan Michaels, University of Michigan, "The Ins and Outs of Cyclical Unemployment"

Building on an idea in Abadie and Gardcazabal (2003), Abadie, Diamond, and Hainmueller investigate the application of synthetic control methods to comparative case studies. They discuss the advantages of these methods and apply them to a study of Proposition 99, a large-scale tobacco control program that California implemented in 1988. They demonstrate that following Proposition 99, tobacco consumption fell markedly in California relative to a comparable synthetic control region. They estimate that by the year 2000, annual per-capita cigarette sales in California were about 26 packs lower than what they would have been in the absence of Proposition 99. Given that many policy interventions and events of interest in social sciences take place at an aggregate level (countries, regions, cities, and so on) and affect a small number of aggregate units, the potential applicability of synthetic control methods to comparative case studies is very large, especially in situations where traditional regression methods are not appropriate. The methods proposed in this article produce informative inference...