3 IZA Discussion Papers
IZA Discussion Paper No. 14398
IZA Discussion Paper No. 12786
published in: ILR Review, 2021, 74 (4), 948-976
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.