3 IZA Discussion Papers
IZA Discussion Paper No. 5372
Endogenous Treatment Effects for Count Data Models with Sample Selection or Endogenous Participation
revised version published in: Health Economics, 2011, 20 (9), 1090-1109
IZA Discussion Paper No. 2867
revised version published in: Health Economics, 2010, 19 (6), 656-669
IZA Discussion Paper No. 2112
published in: Stata Journal, 2006, 6 (2), 156-189