FSS-DECO Seminar – “Adjustment with Many Regressors under Covariate-Adaptive Randomizations” by Prof. Ke MIAO, 22/11/2023, 14:00 @E21B-G002

社會科學學院經濟學系講座：苗克教授，22/11/2023, 14:00 @E21B-G002

Seminar on Economics:

“Adjustment with Many Regressors under Covariate-Adaptive Randomizations”

 

Speaker: Prof. Ke MIAO

Assistant Professor

School of Economics, Fudan University

 

Abstract: Our paper discovers a new trade-off of using regression adjustments (RAs) in causal inference under covariate-adaptive randomizations (CARs). On one hand, RAs can improve the efficiency of causal estimators by incorporating information from covariates that are not used in the randomization. On the other hand, RAs can degrade estimation efficiency due to their estimation errors, which are not asymptotically negligible when the number of regressors is of the same order as the sample size. Ignoring the estimation errors of RAs may result in serious over-rejection of causal inference under the null hypothesis. To address the issue, we develop a unified inference theory for the regression-adjusted average treatment effect (ATE) estimator under CARs. Our theory has two key features: (1) it ensures the exact asymptotic size under the null hypothesis, regardless of whether the number of covariates is fixed or diverges no faster than the sample size; and (2) it guarantees weak efficiency improvement over the ATE estimator without adjustments.

 

Date: 22 Nov 2023 (Wed)

Time: 14:00-15:15

Language: English

Venue: E21B-G002

 

All are welcome!

 

Department of Economics
Faculty of Social Sciences
University of Macau