Unemployment and Tax Design

This paper studies optimal income taxation in an environment where matching frictions generate a trade-off for workers between high wages and low unemployment risk. A higher marginal tax rate shifts the trade-off in favor of low unemployment risk, whereas a higher tax burden or unemployment benefit has the opposite effect. Changes in unemployment generate fiscal externalities, which modify optimal tax formulas. I show that optimal employment subsidies (such as the EITC) phase in with income and that the provision of unemployment insurance justifies a positive marginal tax rate even without income heterogeneity. A calibration exercise to the US economy suggests that optimal transfers for low-income individuals are larger if unemployment risk is taken into account.