Total tax burden includes sales tax that you pay on what you spend, property tax, gas tax, payroll taxes, taxes on utility bills, dog license fees, etc. I don't think 40% is completely far fetched.

Not sure how exactly one would calculate this, though, other than looking at taxes as percentage of GDP and maybe trying to fit yourself in there somehow based on your tax bracket as a ratio to other people. But with an average total tax burden of 26.9% (http://en.wikipedia.org/wiki/List_of_countries_by_tax_revenu...), 40% for someone in an upper bracket doesn't sound so crazy.