Research has long suggested that public employee unions may influence public organization performance by changing the allocation of resources and the management of personnel. Other elements of the governance context, such as the characteristics and behaviors of those who design public policies and run public programs, have less often been considered by researchers, an omission that helps to explain the mixed findings and conflicting conclusions regarding the influence of unions on outcomes. This study develops arguments regarding the impact of governance strategies on the relationship between collective bargaining and organizational performance and tests them in a sample of educational organizations. The results suggest that there is an association between strong teachers' unions and lower student performance, but that the relationship can sometimes be moderated by school boards and superintendents.