We are all supply-siders now

From a great article by David Leonhardt and Geraldine Fabrikant:

In the three decades after World War II, when the incomes of the rich grew more slowly than those of the middle class, the top marginal rate ranged from 70 to 91 percent. Mr. Piketty, one of the economists who analyzed the I.R.S. data, argues that these high rates did not affect merely post-tax income. They also helped hold down the pretax incomes of the wealthy, he says, by giving them less incentive to make many millions of dollars.

Precisely.