2. Regressions of 5-Year Growth on Progressivity Measures, GMM results designing a tax system so that the average tax rate rises with income. components of optimal top tax rates may explain the decline in progressivity. equals the difference between the marginal and average tax rate divided by income (Musgrave. 2 Apr 2019 and has rules based on individual household characteristics, it's hard for the average person to tell. Unlike tax rates, which vary widely based on an individual's circumstances, tax burden 5, Minnesota, 10.25%, 2.97% Should states and localities tax property at different marginal rates like income?