Over the past few years, BIT has implemented a number of successful trials using letters to remind people to pay their taxes. In March 2015, we ran our first trial in Costa Rica. In this case we tested sending emails – an even lower cost intervention than letters.
Working with Anne Brockmeyer and Marco Hernandez from the World Bank, and the tax authority in Costa Rica, we sent emails to 12,515 firms that had failed to submit their 2014 income tax declarations. The tax authority also had third-party information on transactions made by all of these firms from the 2014 tax year (recorded by other firms, state institutions and credit or debit card sales).
Firms were randomly allocated to receive one of: no email; a behaviourally informed email (which was personalised, included a deterrence message, and contained a direct web link); or the same email but additionally including examples of transactions made by the recipient firm and highlighting that these were known by the tax authority in the text.