His research interest includes theoretical and empirical aspects of quantile regression for panel data. His work has been published in the Journal of Econometrics, the Journal of Applied Econometrics, the Journal of Public Economics, the Journal of Development Economics, and the Journal of the American Statistical Association, among others. He is Research Fellow of the Institute for Labor Studies in Germany, Associate Editor of Empirical Economics, and received several research awards for his work on Quantile Regression.