‘The Rich Really Do Pay Lower Taxes Than You” read a headline in the New York Times last fall. This astounding claim, presented in the media as fact and evidence of inequities baked into President Trump’s 2017 tax cut, came from two economists at the University of California, Berkeley. Emmanuel Saez and Gabriel Zucman asserted that 2018 was the first year in U.S. history that the average tax rate on the 400 wealthiest income earners dipped below the rates paid by the lower-middle class and poor.

Finally, we had proof the rich...