Doesn't it depend on what profession you are in?
When I went freelance after years on staff at a newspaper, I never again reached the the same absolute dollar amount. But my net income, after various deductions, was not much different from my wife's, who stayed at the paper. Depended on how much I worked, of course. And it was in Canada, so it might not apply directly; dunno what the tax laws are like here, but I got a few breaks.