Synthetic instruments in DiD designs with unmeasured confounding

jaume vives-i-bastida,Ahmet Gulek

Published 2024 in Social Science Research Network

ABSTRACT

Unmeasured confounding and selection into treatment are key threats to reliable causal inference in Difference-in-Differences (DiD) designs. In practice, researchers often use instrumental variables to address endogeneity concerns, for example through shift-share instruments. However, in many settings instruments may be correlated with unobserved confounders, exhibiting pre-trends. In this paper we explore the use of synthetic controls to address unmeasured confounding in IV-DiD settings. We propose a synthetic IV estimator that partials out the unmeasured confounding and derive conditions under which it is consistent and asymptotically normal, when the standard two-stage least squares is not. Motivated by the finite sample properties of our estimator we then propose an ensemble estimator that might address different sources of bias simultaneously. We illustrate our method through a simulation exercise and two shift-share empirical applications: the Syrian refugee crisis effect on Turkish labor markets and the impact of Chinese imports on US manufacturing employment.

PUBLICATION RECORD

  • Publication year

    2024

  • Venue

    Social Science Research Network

  • Publication date

    Unknown publication date

  • Fields of study

    Not labeled

  • Identifiers
  • External record

    Open on Semantic Scholar

  • Source metadata

    Semantic Scholar

CITATION MAP

EXTRACTION MAP

CLAIMS

  • No claims are published for this paper.

CONCEPTS

  • No concepts are published for this paper.

REFERENCES

Showing 1-42 of 42 references · Page 1 of 1

CITED BY

  • No citing papers are available for this paper.

Showing 0-0 of 0 citing papers · Page 1 of 1