I study how international trade affects labor market outcomes and economic growth. In the first chapter, I study how international trade affects wage inequality within and between firms. Using matched employer-employee data from Germany, I document that the firm-size wage premium is higher for skilled compared to less-skilled workers and that larger firms disproportionately employ more skilled workers. I show, using a new quantitative framework, that non-homothetic production and monopsonistic competition in labor markets can rationalize these reduced-form findings. To estimate the model, I propose a new econometric method to identify non-homotheticity in the presence of upward-sloping labor supply curves separately. Counterfactual exercise...