Trade union densities expressed as wage and salaried employee union members as a share of total salaried and wage employees when available [see data sources’ methodological notes for details: www.oecd.org/dataoecd/37/2/35695665.pdf for OECD data and Baccaro (2008) for IILS data]. Maloney and Ribeiro (1999) find that unions in Mexico increase employment and, correspondingly, Menezes-Filho et al. ( While the effect on profitability is to be expected, the effect on productivity is by no means general.