How Will the Court Decide? - Tax Experts' versus Laymen's Predictions

We conduct a survey of German tax professionals (tax advisors and revenue agents) and laymen to examine whether tax experts more accurately forecast the outcomes of five real cases from the German Federal Fiscal Court. With an average of 2.39 correct predictions among experts and an average of 2.49 correct predictions among laymen, our results reveal no significant difference in forecasting accuracy between the two groups. Additionally, neither general nor task-specific tax expertise increases the experts' forecasting accuracy. This unpredictability of tax court decisions indicates that accounting rules and taxpayer penalties that rely on accurate predictions of tax court decisions may need to be re-evaluated. Moreover, our results indicate the existence of two types of advisor bias'. First, tax advisors exhibit a significantly higher level of overconfidence in comparison to other experts (i.e. revenue agents) and laymen. In particular, they believe that they correctly predict, on average, 1.52 more cases than they actually do. Second, we find some evidence indicating that tax advisors acting as client advocates form stronger appeal recommendations than revenue agents.