What Factors Influence the Structure of the State Income Tax?

This article contributes to a small body of literature that examines empirically the factors affecting the structure of state income taxes. We assume vote-maximizing politicians who are potentially influenced by information spillovers from other states in the spirit of yardstick competition. A number of nominal provisions of the income tax are considered in the empirical analysis, including earned income tax credits, top bracket rates, exemptions, and income thresholds. Politicians manipulate these and other structural features of the income tax to garner votes. The results yield no evidence of yardstick competition in the setting of income tax policy, regardless of how we define neighbors. Political factors like single-party control affect the choice of some tax provisions. Demographic factors play a mixed role; in particular, characteristics of the low-income population are seldom associated with provisions that benefit these particular groups.