EconBase
← All papers

Asymptotic Properties of the Synthetic Control Method

Xiaomeng Zhang, Wendun Wang, Xinyu Zhang

arXiv 22 Nov 2022 · Econometrics · 1 citations (OpenAlex)

arXiv:2211.12095 · PDF · DOI · OpenAlex · Extracted main text

Abstract

This paper provides new insights into the asymptotic properties of the synthetic control method (SCM). We show that the synthetic control (SC) weight converges to a limiting weight that minimizes the mean squared prediction risk of the treatment-effect estimator when the number of pretreatment periods goes to infinity, and we also quantify the rate of convergence. Observing the link between the SCM and model averaging, we further establish the asymptotic optimality of the SC estimator under imperfect pretreatment fit, in the sense that it achieves the lowest possible squared prediction error among all possible treatment effect estimators that are based on an average of control units, such as matching, inverse probability weighting and difference-in-differences. The asymptotic optimality holds regardless of whether the number of control units is fixed or divergent. Thus, our results provide justifications for the SCM in a wide range of applications. The theoretical results are verified via simulations.

Citation extraction

33
references
129
in-text mentions
33
distinct cited
0
self-citations
14,717
main-text words

appendix boundary found by appendix_command · 59% of the source is main text. Read the extracted text to check this.

Most heavily cited references

The works this paper leans on most, across its whole bibliography — not restricted to papers in our corpus. Ranked by composite intensity, which combines how often a work is mentioned, how many sections mention it, and how much of that falls in the main text rather than the appendix.

ReferenceIntensityMentionsSectionsMain text
1B. Ferman and C. Pinto (2021) Synthetic controls with imperfect pretreatment fit1.000273100%
2I. Botosaru and B. Ferman (2019) On the role of covariates in the synthetic control method1.00083100%
3A. Abadie, A. Diamond, and J. Hainmueller (2010) Synthetic control methods for comparative case studies: Estimating the effect of California's tobacco control program1.00073100%
4N. Doudchenko and G. W. Imbens (2016) Balancing, regression, difference-in-differences and synthetic control methods: A synthesis1.00064100%
5B. Ferman (2021) On the properties of the synthetic control estimator with many periods and many controls0.96127589%
6J. Chen (2022) Synthetic control as online linear regression0.87472100%
7C. Hsiao and Q. Zhou (2019) Panel parametric, semiparametric, and nonparametric construction of counterfactuals0.84333100%
8L. Bottmer, G. W. Imbens, J. Spiess, and M. J. Warnick (2021) A design-based perspective on synthetic control methods0.73732100%
9X. Zhang (2021) A new study on asymptotic optimality of least squares model averaging0.73732100%
10Y. Xu (2017) Generalized synthetic control method: Causal inference with interactive fixed effects models0.69351100%

Showing the top 10 of 33 scored citations.

Cited by, within the corpus

arXiv econ.EM papers that cite this one, ranked by how heavily they lean on it.

Citing paperIntensityMentionsSections
1Asymptotic Properties of the Distributional Synthetic Controls0.73732
2Inference in Difference-in-Differences with Few Treated Units and Spatial Correlation0.40511
3Splash! Robustifying Donor Pools for Policy Studies0.40511
4The inclusive Synthetic Control Method0.40511
5Debiasing and $t$-tests for synthetic control inference on average causal effects0.00011