Utilities to automate synthetic control estimation. Stata module to implement synthetic control methods. On the failure of the bootstrap for matching estimators with g. Synthetic control method synth is a statistical software package for r, stata, and matlab that implements synthetic control methods for causal inference in comparative case studies as described in abadie and gardeazabal 2003, abadie, diamond, and hainmueller2010, abadie, diamond, and hainmueller 2011, and abadie, diamond, and hainmueller 20. Has anyone worked much with synthetic control estimation using the procedure in the 2010 jasa by abadie and coauthors. Synthetic control methods in comparative case studies in r a datadriven control group selection procedure, a framework for assessing the suitability of the chosen control group, and a means of producing quantitative inference. Many additional explanations, in particular on how to select potential comparison units and predictor variables, are provided in abadie et al. This module should be installed from within stata by typing ssc install synth. The r package synth implements synthetic control methods for comparative case studies designed to estimate the causal e ects of policy interventions and other events of interest abadie and. Placebo tests in synthetic control method cross validated. Stata module to implement synthetic control methods for comparative case studies, statistical software components s457334, boston college department of economics, revised 28 jan 2014. Ifc statistical software components from boston college department of economics.
The r package synth implements synthetic control methods for comparative case studies designed to estimate the causal effects of policy interventions and other events of interest abadie and gardeazabal 2003. I discuss the advantages of this method over the one. I am trying to make graphs for the placebo tests under synthetic control, however i seem to be doing something wrong as i am not being able to merge the files. Utilities to automate synthetic control estimation using synth. We explore the pros and cons of two counterfactual analysis methodologies the panel data approach pda and the synthetic control method scm through a discussion of the differences in their underlying assumptions and a series of simulations. In this paper, we propose a method that not only relaxes this oftenviolated assumption, but also unifies the synthetic control method abadie, diamond, and hainmueller 2010 with linear fixed effects models under a simple framework, of which did is a special case. Nonparametric synthetic control method for program. Comparative politics and the synthetic control method. Jens hainmueller has code for it on his website for those curious to look at it in action. Alberto abadies research works massachusetts institute of. This approach imputes the missing counterfactual status of a specific treated unit as a weighted average of a number of control units the socalled donors pool. Building on an idea in abadie and gardeazabal 2003, this article investigates the application of synthetic control methods to comparative case studies.
Estimating the effect of californias tobacco control program. Abadie, diamond, and hainmueller, 2010, journal of the american statistical association 105. View notes abadie et al 2009 synthetic control cigarettes in ca from econ 191 at university of california, berkeley. Comparative politics and the synthetic control method by. Alberto abadie, alexis diamond and jens hainmueller additional contact information alexis diamond. We discuss the advantages of these methods and apply them to study the effects of proposition 99, a largescale tobacco control program that california implemented in 1988.
Stata module to implement synthetic control methods for comparative case studies. Mar 18, 2018 the synthetic control methodology abadie and gardeazabal, 2003. The synth package for r is also described in detail in abadie,diamond, and hainmueller 2011. Synthetic control methodology as a tool for evaluating. In this article, i introduce the itsa command, which performs interrupted timeseries analysis for single and multiplegroup comparisons. Building on the paper by abadie and gardeazabal 2003 and abadie, diamond, and hainmueller 2010, i extend the synthetic control method for program evaluation to the case of a nonparametric identification of the synthetic or counterfactual time pattern of the treated unit for instance. A flexible synthetic control method for modeling policy. As a prerequisite, the synth package needs to be installed. Formerly mit political science department research paper no. The basic idea behind synthetic controls is that a combination of units often provides a better comparison for the unit exposed to the intervention than any single unit alone. An r package for synthetic control methods in comparative case studies.
Abadie et al 2009 synthetic control cigarettes in ca. I am using the dataset of abadie 2010 and using the command given under help synth to perform the placebo tests, however i am not sure on how to proceed. In the scm approach, the synthetic control unit is created out of a collection of jcontrol units, the socalled donor pool. We illustrate the main ideas behind the synthetic control method by estimating the economic impact of the 1990 german reunification on west germany. Synthetic control methods abadie and gardeazabal, 2003. The comparability of the synthetic control unit to the treated unit in the preintervention period is determined by a set of predictors from tpretreatment periods. A penalized synthetic control estimator for disaggregated data with j. Estimating the effect of californias tobacco control program with a. The synthetic control method scm abadie and gardeazabal, 2003, abadie et al. Oct 28, 2011 abadie, alberto and diamond, alexis j. The synthetic control method as a tool to understand state policy.
Abadie and gardeazabal 2003 pioneered a synthetic control method when estimating the effects of. Synthetic control modeling questions economics job market. Abadie and gardeazabal 2003 pioneered a synthetic control method when estimating the effects of the terrorist conflict in the basque country. The synthetic control method as a tool to understand state policy identifying good governance depends on accurately evaluating policies for their efficiency and effectiveness, and many tools are available for that purpose. Panel data approach vs synthetic control method sciencedirect. Sebastian galiani university of maryland brian quistorff university of maryland march 15, 2016 abstract the synthetic control methodology abadie and gardeazabal, 2003. Synth is a statistical software that implements synthetic control methods for causal inference in comparative case studies with aggregate data as described in abadie and gardeazabal 2003, abadie, diamond, and hainmueller 2010, and abadie, diamond, and hainmueller 20. By alberto abadie, alexis diamond and jens hainmueller.
To ensure that the global minimum in the parameter space. Estimating the effect of californias tobacco control. Synthetic control methods for comparative case studies. Apr 10, 2020 automation for multiple synthetic control estimations in stata. The synthetic control method builds a counterfactual using a weighted combination of potential control units. Conducting interrupted timeseries analysis for single.
If the magnitude of the difference remains in favor of the original treatment group, you can claim that there is a treatment effect. Massachusetts institute of technology department of economics the morris and sophie chang building e52300 50 memorial drive cambridge, ma 02142. Hi statalist users, im using the synth command synthetic control for a balanced panel data and facing the following situation. Balancing, regression, differenceindifferences and. First, we propose parametric weights for the pvalue that includes the equal weights benchmark of abadie et al. Instrumental variable estimation with firststage heterogeneity with j. We extend the inference procedure for the synthetic control method in two ways. First, we implement the synthetic control method with the stata package synth, 18 replicating the specifications used in abadie et al, 10 in which predictors of cigarette sales include retail. The all option is necessary to install the accompanying dataset used in further examples. Estimating the effect of californias tobacco control program alberto abadie, alexis diamond, and jens hainmueller nber working paper no. In a seminal paper abadie, diamond, and hainmueller 2010 adh, see also abadie and gardeazabal 2003, abadie et al. An application to minimum wage policies we propose a simple, distributionfree method for pooling synthetic control case studies.
In the following, we describe how synthetic control methods work both with and without the crossvalidation technique. The inclusion of a counterfactual improves causal inference for approaches based on time series analysis, but the selection of a suitable counterfactual or control area can be problematic. It imputes counterfactuals for each treated unit using control group information. Synth is a statistical software that implements synthetic control methods for causal inference in comparative case studies with aggregate data as described in abadie and gardeazabal 2003, abadie, diamond, and hainmueller2010, and abadie, diamond, and hainmueller 20.
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