Many people earn high incomes because that is what they do. They can't slow down, 39% tax or 75% tax they do their thing and the money rolls in. As long as tax rates don't exceed 99% they still make more money so why stop. Someone who makes $100 million can probably survive on $1 million. If they slow down and "only" earn $50 million, five hundred thousand wont be enough so the have to work hard enough to make that $100 million. We wont know until we try it.