Loss aversion and indifference to tax rates: Evidence from tax filing data

A fundamental tenet of economics is that agents respond to incentives. When filing their tax returns, Swedish taxpayers get information about whether they are below or above a salient tax kink, information that could affect tax-filing behavior. Ceteris paribus, rational taxpayers would be more likely to claim deductions when facing a higher marginal tax rate. They also get informed whether they can expect a tax refund or have taxes due. This information would be of no importance to rational individuals, but a loss averse taxpayer would be more likely to claim deductions if having taxes due than if expecting a refund. We study the probability of claiming deductions in an RDK framework using register data on the universe of Swedish taxpayers over an eight-year period. We find a strong causal effect of taxes due, while the response to the marginal tax kink is insignificant. The results are similar for inexperienced (young) and experienced (old) taxpayers. Hence, loss aversion is much more decisive than standard economic incentives in predicting deduction behavior.