This article assesses the relationship between national and collective bargaining institutions, management practices, and employee turnover, based on case study and survey evidence from U.S. and German call center workplaces. German call centers were more likely to adopt high-involvement management practices than those in the United States, even across workplaces with no collective bargaining institutions. Within Germany, union and works council presence was positively associated with high-involvement practices, while works council presence alone had no effect. In contrast, union presence in U.S. call centers showed either a negative association or no association with these practices. National and collective bargaining institutions and high-involvement management practices were associated with lower quit rates in both countries, with only partial mediation.