This thesis consists of three chapters. The first chapter studies the effects of an integration of local labor markets between France and Switzerland. It shows that removing barriers to worker mobility can improve the labor market outcomes of workers, even of those that do not move. The reason is that the option to work at a larger number of employers decreases a single firm’s wagesetting power. The second chapter estimates the elasticity of labor supply to individual firms in Switzerland with a discrete choice model where workers have correlated preferences across firms. The results show that allowing for correlated worker preferences across firms in the model increases the estimated degree of competition in the labor market. The last chap...