我们研究了加拿大和美国工会化和工资不平等之间不断变化的关系。我们研究的动机是最近工会劳动力构成的深刻变化。从历史上看，工会工作主要集中在私营行业的低技能男性身上。随着私营部门工会人数的稳步下降和在公共部门的影响力不断上升，两国的公共部门工会人数现在是私营部门工会人数的五倍。虽然公共部门只占就业的15-20%，但有一半的工会工人在公共部门工作。伴随这些变化的是妇女在工会工人中所占比例的显著上升。目前，北美大约一半的工会成员是女性。虽然早期关于工会和不平等的研究主要关注男性，但最近的研究同时考察了这两者，并揭示了显著的性别差异。一项一致且令人困惑的发现是，工会减少了男性的工资不平等，但没有减少女性的。在这两个国家，我们发现私营部门和公共部门在工会化对工资不平等的影响方面存在显著差异。 These differences have become more pronounced over time. At present, unions reduce economy-wide wage inequality by less than 10% in both countries. However, union impacts on wage inequality are much larger in the public sector. Once we disaggregate by sector the effects of unions on male and female wage inequality no longer differ. The key differences in union impacts are between the public and private sectors - not between males and females.