Data and Code for: The Costs of Corporate Tax Complexity

Does tax code complexity alter corporate behavior? We investigate this question by studying the decision to claim refunds for tax losses. In a sample of 1.2M observations from the population of corporate tax returns, only 37 percent of eligible firms claim their refund. A simple cost-benefit analysis of the tax loss choice cannot explain low take-up, motivating an exploration of how complexity alters this calculation. Research designs exploiting tax preparer switches, deaths, and relocations show that sophisticated preparers increase claim rates for small firms. Imperfect take-up has implications for measuring marginal tax rates and for the design of fiscal policy.