One Size Does Not Fit All: A Field Experiment on the Drivers of Tax Compliance and Delivery Methods in Rwanda

Although field experiments in tax compliance represent a growing area of research, the literature has so far focussed exclusively on high and middle-income countries. This paper starts to fill this gap by reporting the results of a tax field experiment in Rwanda, while also highlighting some characteristics that may be common to other low-income countries. We evaluate an intervention carried out by the Rwanda Revenue Authority (RRA), which involved sending messages to taxpayers to nudge their declaration behaviour during the filing period of January-March 2016. Focussing particularly on business profits tax, our study is designed to address two interrelated questions. First, what are the key drivers of compliance in Rwanda? Second, what is the best delivery method to reach taxpayers with messages designed to improve compliance? Although other studies have explored delivery methods in the context of taxpayer communication, our study is the first one to interact these methods with different message contents. As a result, we evaluate a set of nine treatments that combine three message contents (deterrence, fiscal exchange, reminders) and three delivery methods (letters, SMS, emails) – as compared to a control group that received no message. We find that friendly approaches to taxpayers are generally more effective than deterrence. However, small taxpayers are still quite responsive to the possibility of being fined and prosecuted (deterrence). We also show that low-cost delivery methods like SMS and emails can be highly effective as compared to letters.