Complexity of Personal Income Tax Design: An Index of Measurement

Abstract

This article puts forward an index of complexity of personal income tax design. Deductions and tax exemptions, etc., are often linked to legal tax brackets in order to increase fairness in the distribution of tax burden. But increased fairness tends to make the tax structure less comprehensible to the non-perfectly informed taxpayer. The proposed index gives a quantitative measurement of the distortion between legal and effective tax rates along the gross income scale and allows for intertemporal and interspatial comparisons. An application of the index to Italian personal income tax concludes the article.