Research Interests:

Efficient estimation of time series models with conditional heteroskedasticty of unknown form; Small sample properties and small sample refinements of moment based estimators of time series models, including bias correction and moment selection; Estimation of dynamic panel models, bias corrections for ML and GMM estimators of dynamic panel models, Analysis of weak instrument problems in the dynamic panel model; Analysis of finite sample properties of various estimators for simultaneous equations models; Bootstrap and Jackknife based bias correction for maximum likelihood estimators. Size corrections for Wald tests. Non-parametric testing procedures for causal inference.

 

Papers and Research

Causal Effects of Monetary Shocks: Semiparametric Conditional Independence Tests with a Multinomial Propensity Score” (with Joshua Angrist), IZA Discussion Paper No. 3606. pdf

 

Semiparametric Causality Tests Using the Policy Propensity Score” (with Joshua Angrist), NBER Working Paper 10975. pdf

 

 “Bias Reduction for Dynamic Nonlinear Panel Models with Fixed Effects” (with Jinyong Hahn). pdf  Supplementary Appendix

 

“Selecting the Number of Instruments for GMM Estimators of Linear Time Series Models.”

 

“Higher Order Efficiency of Bias Corrections” (with Jinyong Hahn and Whitney Newey). pdf

 

“Mean Squared Error Reduction for GMM Estimators of Linear Time Series Models” pdf   Tables

 

Publications

“Difference in Difference meets Generalized Least Squares: Higher Order Properties of Hypotheses Tests” (with Jerry Hausman), Journal of Econometrics, 144 (2008), 371-391. pdf

 

“Long difference instrumental variables estimation for dynamic panel models with fixed effects,” (with Jinyong Hahn and Jerry Hausman), Journal of Econometrics, 140 (2007), 574-617. Supplementary Appendix

 

“Automatic Inference for Infinite Order Vector AutoregressionsEconometric Theory, 21 (2005), 85-115. pdf

 

“Estimation with Weak Instruments: Accuracy of Higher Order Bias and MSE Approximations,” (with Jinyong Hahn and Jerry Hausman), Econometrics Journal, 7 (2004), 272-306. pdf

 

“Asymptotic Distribution of Misspecified Random Effects Estimator for a Dynamic Panel Model with Fixed Effects When Both n and T are Large” (with Jinyong Hahn and Myeong Hyeon Cho), Economics Letters, 84 (2004), 117-125. pdf

 

“Moment Selection and Bias Reduction for GMM in Conditionally Heteroskedastic Models,” forthcoming in “Econometric Theory and Practice: Frontiers of Analysis and Applied Research: Essays in Honor of Peter C.B. Phillips”, D. Corbea, S. Durlauf and B.E. Hansen (eds), Cambridge University Press. pdf

 

“Discontinuities of Weak Instrument Limiting Distributions,” (with Jinyong Hahn), Economics Letters, 75 (2002), 325-331. pdf

 

“Asymptotically Unbiased Inference for a Dynamic Panel Model with Fixed Effects when both n and T are large,” (with Jinyong Hahn), Econometrica, 70 (2002), 1639-1657. pdf

 

“Efficient Instrumental Variables Estimation for Autoregressive Models with Conditional Heteroskedasticity,” Econometric Theory, 18 (2002), 547-583. pdf Tables

 

“Optimal Instrumental Variables Estimation for ARMA Models,” Journal of Econometrics, 104(2) (2001), 359-405. pdf Tables 1 Tables 2 Graphs

 

“Interest rates and exchange rates under money supply targets,” (with Walter Wasserfallen), Journal of Monetary Economics, 33 (1994), 201-230.

 

“Real Business Cycle Models - Some Evidence for Switzerland,” (with Marcel Rindisbacher), Swiss Journal of Economics and Statistics, 130 (1994), 21-43.

 

 

 

 

Where indicated in the papers this material is based upon work supported by the National Science Foundation under Grant No. 0095132 and 0523186.