If you honestly believe that such a massive tax increase would have zero effect on peoples' behavior I have a bridge to sell you.
That change in "behavior" is largely more aggressive attempts to exploit loopholes in the tax code, not actual reductions in taxable income by "working less" as conservatives like to claim. Close the loopholes and you will see more revenue from tax increases.
Btw, can we really even call it an "increase" if all we're doing is telling rich people to pay taxes on the same proportion of their income as you and i do? I'd call it "shoring up regressive policy."
I'd be fine with a tax increase as long as it was tied to a spending cut, like slightly raising the age of eligibility.
You cant even receive partial benefits until you are 62. We only live to 78 in this country (4+ years shorter than nations with better healthcare systems). How miserable and short do you want our retirement years to be?