Score contribution per author:
α: calibrated so average coauthorship-adjusted count equals average raw count
This paper presents results from two large-scale natural field experiments that tested the effect of social norm messages on tax compliance. Using administrative data from >200,000 individuals in the United Kingdom, we show that including social norm messages in standard reminder letters increases payment rates for overdue tax. This result offers a rare example of social norm messages affecting tax compliance behavior in a real world setting. We find no evidence that loss framing is more effective than gain framing. Descriptive norms appear to be more effective than injunctive norms. Messages referring to public services or financial information also significantly increased payment rates. The field experiments accelerated the collection of tax revenue at little cost.