3 IZA Discussion Papers
IZA Discussion Paper No. 10713
published in: International Journal of Manpower 2019, 40 , 850–878
IZA Discussion Paper No. 9221
revised version published as 'Union Membership Density and Wages: The Role of Worker, Firm, and Job-Title Heterogeneity' in: Journal of Econometrics. 2023, 233 (2), 612-632.
IZA Discussion Paper No. 1957
published in: Industrial and Labor Relations Review, 2007, 60 (2), 246-267