Tax progressivity and mobility costs

This paper examines how mobility costs influence the effectiveness and desirability of tax progressivity using a general equilibrium spatial model. A key feature of the model is that workers' idiosyncratic productivity depends on location. The interaction of amenities, idiosyncratic shocks and moving costs implies that progressive taxation distorts location choices by reducing incentives for agents to relocate to their most productive areas. Using a quantitative framework, I find that the negative effect of tax progressivity on output is weakest when mobility costs are either relatively low or high. The optimal degree of tax progressivity balances the costs of spatial tax distortions against the benefits of enhanced insurance, leading to relatively high optimal progressivity at both extremes of mobility costs.