It did? The paper under discussion doesn't really give an answer and first paper I can find that does, about the 1986 tax reform (admittedly it's not about the

It did? The paper under discussion doesn't really give an answer and first paper I can find that does, about the 1986 tax reform (admittedly it's not about the 1964 reform when top rates were even higher), states that "The estimated sensitivity implies that a change in income tax rates has substantially less impact on tax revenue than would be true if there were no behavioral response to marginal tax rates. This sensitivity of taxable income also implies that high marginal tax rates create significant deadweight losses by inducing taxpayers to act differently than they otherwise would.'" But I have no skin in this game and I'm not being obtuse, happy to learn more.