2 IZA Discussion Papers
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. 4278
published in: Labour, 2011, 25 (2), 182-197