Working Papers

1. Doubly Robust Difference-in-Differences Estimators, November 2018 (joint with Jun B. Zhao).
[Supplementary Appendix]

2. Covariate Distribution Balance via Propensity Scores, August 2018 (joint with Xiaojun Song and Qi Xu).
[Supplementary Appendix]

3. Difference-in-Differences with Multiple Time Periods and an Application on the Minimum Wage and Employment, August 2018 (joint with Brantly Callaway). First version: March 2018 .
[Supplementary Appendix] [Software implementation: R package did ]

4. Nonparametric Tests for Treatment Effect Heterogeneity with Duration Outcomes, April 2017.
This is a revised version of my JMP, “Nonparametric tests for conditional treatment effects with duration outcomes”, November 2014.
[ Supplementary Appendix] [ Software implementation: R package kmte ]

5. Specification Tests for the Propensity Score, November 2016 (joint with Xiaojun Song).
[Software implementation: R package pstest]

6. Program Evaluation with Right-Censored Data, April 2016.
[Supplementary Appendix] [Software implementation: R package kmte]


7. Testing for Uncorrelated Residuals in Dynamic Count Models with an Application to Corporate Bankruptcy, 2017. Journal of Business & Economics Statistics, vol. 35 (3), 349-358.
[Replication files available upon request]