Guido Imbens

Overview

Guido W. Imbens is Applied Econometrics Professor at Stanford Graduate School of Business and a Research Associate at NBER. He is a leading theorist of causal inference methods in econometrics, with foundational contributions to instrumental variables, matching estimators, regression discontinuity, and difference-in-differences. In 2021 he shared the Nobel Memorial Prize in Economic Sciences with David Card and Joshua Angrist for methodological contributions to the analysis of causal relationships — specifically for the LATE framework developed jointly with Angrist.

Key Contributions / Features

• LATE — with Angrist (Econometrica 1994), defined the IV estimand as the average treatment effect for compliers; introduced monotonicity as the key assumption; the paper for which the 2021 Nobel was primarily awarded
• AIR (1996) framework — with Angrist and Rubin (JASA 1996), embedded LATE in the Rubin Causal Model; formalized the five assumptions; introduced the compliance typology (compliers, never-takers, always-takers, defiers); derived sensitivity propositions for exclusion restriction and monotonicity violations
• Matching estimators — with Abadie (Econometrica 2006; JBES 2011), developed large-sample properties of nearest-neighbor matching estimators for ATE and ATT; bias-corrected matching
• Regression discontinuity — foundational econometric contributions to the formal framework for sharp and fuzzy RD; bandwidth selection; nonparametric identification
• Difference-in-differences — recent theoretical work on parallel trends, staggered adoption, and heterogeneous effects

Related

• Instrumental Variables
• Local Average Treatment Effect
• Rubin Causal Model
• Joshua Angrist
• Donald Rubin

Sources

• Angrist Imbens and Rubin 1996 — Identification of Causal Effects Using Instrumental Variables
• Angrist Imbens and Rubin 1996 — Identification of Causal Effects Using Instrumental Variables Rejoinder
• Heckman 1996 — Identification of Causal Effects Using Instrumental Variables Comment
• Heckman 2008 — Econometric Causality
• Moffitt 2005 — Remarks on the Analysis of Causal Relationships in Population Research
• Robins and Greenland 1996 — Identification of Causal Effects Using Instrumental Variables Comment