Synthetic Control Methods for Comparative Case Studies: Estimating the Effect of California's Tobacco Control Program

51 Pages Posted: 23 Jan 2012 Last revised: 23 Jan 2022

See all articles by Alberto Abadie

Alberto Abadie

Harvard University - Harvard Kennedy School (HKS); National Bureau of Economic Research (NBER)

Alexis Diamond

Harvard University

Jens Hainmueller

Stanford University - Department of Political Science; Stanford Graduate School of Business; Stanford Immigration Policy Lab

Multiple version iconThere are 2 versions of this paper

Date Written: January 2007

Abstract

Building on an idea in Abadie and Gardeazabal (2003), this article investigates the application of synthetic control methods to comparative case studies. We discuss the advantages of these methods and apply them to study the effects of Proposition 99, a large-scale tobacco control program that California implemented in 1988. We demonstrate that following Proposition 99 tobacco consumption fell markedly in California relative to a comparable synthetic control region. We 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, etc.) 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 regardless of the number of available comparison units, the number of available time periods, and whether the data are individual (micro) or aggregate (macro). Software to compute the estimators proposed in this article is available at the authors' web-pages.

Suggested Citation

Abadie, Alberto and Diamond, Alexis J. and Hainmueller, Jens, Synthetic Control Methods for Comparative Case Studies: Estimating the Effect of California's Tobacco Control Program (January 2007). NBER Working Paper No. w12831, Available at SSRN: https://ssrn.com/abstract=1990083

Alberto Abadie (Contact Author)

Harvard University - Harvard Kennedy School (HKS) ( email )

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Alexis J. Diamond

Harvard University ( email )

Jens Hainmueller

Stanford University - Department of Political Science ( email )

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Stanford Graduate School of Business ( email )

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Stanford Immigration Policy Lab

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