This study evaluates the impact of behavioural interventions on the uptake and payment of tax arrears through an amnesty program in Kenya. Using a randomised controlled trial, 43,666 tax delinquents from Nairobi region were evaluated. Taxpayers were assigned to receive either a neutral informational email, one of three behavioural messages on deterrence, social norms, payment plans, or no message at all. The experiment was conducted over three treatment rounds between December 2023 and May 2024, allowing for the analysis of both immediate effects and sequencing dynamics. Non respondents were re-randomised across message types in the final round. Results show that all message treatments significantly increased amnesty uptake relative to no communication. Additionally, deterrence messages were more effective than social norms or payment plan reminders. Changing message framing in the third round enhanced participation among late responders but was associated with smaller payments relative to early takers. Overall, the findings suggest that while behavioural messages can promote engagement, informational communication may be equally effective in improving compliance. The study contributes to the literature by highlighting the effectiveness of behavioural intervention in an amnesty context and illustrates the importance of message sequencing in sustaining taxpayer attention.
Treat Remind Repeat!
A Natural Field Experiment in a Tax Amnesty Context
- Gayline Vuluku
- Erich Kirchler
- Christian Bauer