Revenge, tax informing, and the optimal bounty

A common belief is that the IRS pays tax informants 10% of whatever their tips produce in revenue. Actually, the bounty rate is even lower, averaging, in recent years, less than 2% of the amount of taxes and fines recovered. Why is it that the IRS is so tightfisted in rewarding informants who help recover taxes that otherwise would not have been recovered? The present paper approaches this question from an economic perspective, introducing a simple model of the informing decision, the implications of which are incorporated into the tax administration's problem of selecting a bounty rate, as well as a probability of convicting informed-upon evaders, that maximize its expected net revenues from tax informing. The paper shows that a revenue-maximizing tax administration would set its bounty rate lower and its prosecution efforts higher, the stronger, at the margin, informants' desire to get revenge on former parties with whom they have quarreled. While the IRS may be guided by ethical and moral considerations in designing its bounty scheme, it nevertheless behaves as if it were cynically exploiting informants' emotional drives, cutting down on their fair share in the recovered amounts to help finance its efforts in prosecuting informed-upon evaders.