Abstract: The complexity of the income tax is an unending source of complaint, and compliance costs are estimated to be very large. Yet most recognize that some degree of complexity is necessary if income is to be measured accurately. This article presents a framework for analyzing the value of greater accuracy in income taxation. Formulations for both distributive and incentive benefits of accuracy are offered. In addition, the article takes into account that compliance costs and the effects of complex provisions are endogenous, determined in significant part by taxpayers' information acquisition efforts. The article addresses whether taxpayers have excessive or inadequate incentives to acquire information about taxable income and to challenge tax assessments.