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)).