This dissertation is about questions on how German institutions of industrial relations shape plant-level outcomes, and how this influences employer wage differentials. Employer wage differentials point toward imperfect labor markets in which both, employers and employees, benefit from employment rents. It puts the employer at the center of explaining wage differences and how employer characteristics influence these, over which individual employees have only limited control. Arguably, how employers and employees split these rents depend on industrial relations. The German dual model of industrial relations consists of collective bargaining at the industry level and worker co-determination through works councils at the plant level. This dissertation illuminates different aspects of industrial relations and how rent-sharing mechanisms can explain wage inequality in Germany. It does not only focus on how industrial relations shape labor market power and whether labor market power translates into the level and dispersion of employer wage premia. It also contributes to questions that explain differences in plant-level outcomes relating to industrial relations. These include the role of worker co-determination on assortative matching. It is further investigated how works councils affect plant-level reactions during economy-wide shocks. In addition, it offers new causal evidence of rent-sharing mechanisms in Germany. The insights of this dissertation are relevant for policy and economic research alike. It contributes to a better understanding of the role of organized labor in imperfect labor markets and its determinants of employer wage differentials. It approaches the role of worker co-determination from different angles that are important at times of erosion of formal organized labor but gaining interest in worker representation.