That’s what Gerald Auten and David Splinter argue in a paper from last year.
… new estimates of top income shares using two consistent measures of income. Our measure of consistent market income includes full corporate profits and adjusts for changes from TRA86, including changes to the tax base and increased filing by dependent filers. In addition, we include employer paid payroll taxes and health insurance and adjust for falling marriage rates. The effect of these adjustments on estimated top income shares are dramatic. Using a consistent measure of market income shows that the increase in income shares of the top one percent since 1979 is about half of the PS unadjusted estimate. The increase since 1960 is about one-quarter of the unadjusted estimate. Moreover, our measure of broad income that includes government transfers reduces the top one percent share increase to one-tenth of the unadjusted estimate.
But in an NBER working paper, Annette Alstadsaeter, Niels Johannesen, and Gabriel Zucman argue that tax evasion and offshore wealth holdings work in the opposite direction:
Because offshore wealth is very concentrated at the top, accounting for it increases the top 0.01% wealth share substantially in Europe, even in countries that do not use tax havens extensively. It has considerable effects in Russia, where the vast majority of wealth at the top is held offshore. These results highlight the importance of looking beyond tax and survey data to study wealth accumulation among the very rich in a globalized world.
explore the intellectual and political debates surrounding the taxation of the wealthy while also providing the most detailed examination to date of when taxes have been levied against the rich and when they haven’t. Fairness in debates about taxing the rich has depended on different views of what it means to treat people as equals and whether taxing the rich advances or undermines this norm. Scheve and Stasavage argue that governments don’t tax the rich just because inequality is high or rising—they do it when people believe that such taxes compensate for the state unfairly privileging the wealthy. Progressive taxation saw its heyday in the twentieth century, when compensatory arguments for taxing the rich focused on unequal sacrifice in mass warfare. Today, as technology gives rise to wars of more limited mobilization, such arguments are no longer persuasive. [Text from the Publisher’s website.]
In the NZZ, Marius Brülhart and Kurt Schmidheiny discuss the Swiss experience with a federalist tax system. Cantonal and municipal taxes average roughly 40 percent of the total tax take in Switzerland, see the first figure.
The decentralized tax system, tax competition between cantons and communities as well as mobility of high income tax payers imply that the effective average income tax rate substantially falls short of the unweighted average tax rate on high incomes. In fact, the effective average tax rate is degressive for high incomes, see the second figure (which the authors reproduce from an article by Roller and Schmidheiny (2015)).
They are higher than many people outside of Switzerland suspect. Moreover, their cantonal and municipal components vary considerably across regions. Iwan Städler’s report in the Tagesanzeiger Blog provides an interactive graphic.
The federal tax levy can be computed using this tool.