Effects of electronic cash registers on reported revenue

We assess the impact of a Swedish regulatory change, which required businesses with any business-to-consumer transactions, whether by cash or card, to use a certified electronic cash register (ECR), on reported revenue. To do this, we use administrative data on the monthly reported revenue of all affected firms and a staggered difference-in-differences approach. Our findings indicate that there was an immediate increase of about 2.7–4.3% in reported revenue following the implementation of a certified ECR. However, the effect was temporary and diminished to zero after just a few months, which indicates that firms found innovative methods to underreport their revenue.