"All this has major implications for the U.S. Consider California, which just enacted higher rates of income and sales tax. The top California income-tax rate will be 13.3%, and the top sales-tax rate in some areas may rise as high as 10%. Combine these state taxes with a top combined federal rate of 44%, plus federal excise taxes, and the combined marginal tax rate for the highest California earners is likely to be around 60%—as high as in France, Germany and Italy."
Prescott and Ohanian: Taxes Are Much Higher Than You Think