This dissertation examines three topics in macroeconomics. The first chapter studies the impact of severance payments on employment when firms can subcontract as a substitute for hiring workers. In countries with strict job security regulations firms use flexible staffing arrangements to buffer the regular workforce from economic fluctuations and avoid workers' firing costs. I set up a general equilibrium model in the tradition of Hopenhayn and Rogerson (1993) where firms can hire two types of workers: subcontractors that are totally flexible, and permanent workers that entail firing costs that increase with seniority in the job. Both types are perfect substitutes in production, but permanent workers are relatively less expensive as subc...