2 IZA Discussion Papers
IZA Discussion Paper No. 6480
revised version published in: Journal of Labor Economics, 2015, 33(3), 521-569
IZA Discussion Paper No. 947
substantially revised version published as 'Heterogeneity and Performance in Tournaments: A Test for Incentive Effect using Professional Tennis Data' in: Applied Economics, 2010, 41 (25), 3199-3208