You've Got Mail: A Randomized Field Experiment on Tax Evasion

We report from a large-scale randomized field experiment conducted on a unique sample of more than 15,000 taxpayers in Norway who were likely to have misreported their foreign income. By randomly manipulating a letter from the tax authorities, we cleanly identify that moral suasion and the perceived detection probability play a crucial role in shaping taxpayer behavior. The moral letter mainly works on the intensive margin, while the detection letter has a strong effect on the extensive margin. We further show that only the detection letter has long-term effects on tax compliance.