Tax advice and reporting under uncertainty: Theory and experimental evidence

This study extends the Beck, Davis, and Jung (1992) experimental study by incorporating opportunities for taxpayer subjects to purchase advice before making their tax reporting decisions. Tax advice has two roles in the model and experiment. First, tax advice allows taxpayers to reduce their uncertainty about the amount of taxes owed. This permits us to study the demand for tax advice in conjunction with its effect on tax reporting decisions. Second, the decision to purchase tax advice from an expert provides a means of signaling that may alter tax agency audit policies. The resulting audit policies, in turn, can affect taxpayers' decisions to purchase tax advice. These interdependencies are incorporated in a game-theoretic model and several predictions are tested experimentally. Consistent with theory, subjects sorted themselves into three groups based upon their private information. Another prediction supported by the experiment is that the demand for tax advice increased with the magnitude of an uncertain tax deduction (amount-at-risk). We also found, as expected, that the effects of tax advice on pre-audit tax revenues depend upon the amount-at-risk. When the amount-at-risk was high, subjects in settings with tax advice reported lower average incomes and paid lower taxes than did those subjects in settings without the opportunity to purchase tax advice. The opposite was true for the low amount-at-risk condition, supporting our prediction that tax advice and amount-at-risk would have an interactive effect on tax reporting. Analysis was also performed on post-audit tax collections. Contrary to theory, post-audit tax payments were found to increase when subjects had an opportunity to purchase tax advice. This result apparently was caused by a tendency to over-purchase tax advice and, in some cases, to report a low income regardless of the advice received.