This article examines how collective bargaining through unions and workplace codetermination through works councils relate to labor market imperfections and how labor market imperfections relate to employer wage premia. Based on representative German plant data for the years 1999-2016, the authors document that 70% of employers pay wages below the marginal revenue product of labor and 30% pay wages above that level. Findings further show that the prevalence of wage markdowns is significantly smaller when organized labor is present, and that the ratio of wages to the marginal revenue product of labor is significantly larger. Finally, the authors document a close link between labor market imperfections and mean employer wage premia, that is, wage differences between employers corrected for worker sorting.