We use variation in the degree of development of local credit markets and matched employer–employee data to assess the role of the firm as an internal credit market. We find that firms operating in less financially developed markets offer lower entry wages but faster wage growth than firms in more financially developed markets. This helps firms finance their operations by implicitly raising funds from workers. We control for local market fixed effects and only exploit time variation in the degree of local financial development induced by an exogenous liberalization, so that the effect we find is unlikely to reflect unobserved local factors that systematically affect wage–tenure profiles. We estimate that the amount of credit generated by implicit lending within the firm is economically important and can be as large as 30 percent of the bank lending. Consistent with credit market imperfections opening up trade opportunities within the firm, we find that the internal rate of return of implicit loans lies between the rate at which workers savings are remunerated in the market and the rate that firms pay on their loans from banks.

We show that the effects of taxes on labor supply are shaped by interactions between adjustment costs for workers and hours constraints set by firms. We develop a model in which firms post job offers characterized by an hours requirement and workers pay search costs to find jobs. We present evidence supporting three predictions of this model by analyzing bunching at kinks using Danish tax records. First, larger kinks generate larger taxable income elasticities. Second, kinks that apply to a larger group of workers generate larger elasticities. Third, the distribution of job offers is tailored to match workers' aggregate tax preferences in equilibrium. Our results suggest that macro elasticities may be substantially larger than the estimates obtained using standard microeconometric methods.