The top 1 percent of earners pay about 40 percent of all income taxes, which comes out to about $540 billion a year. You could tax away every penny they earned, and it would still not come close to paying for a full-fat UBI, in other words. “Nothing in the history of this country suggests Americans are ready to add that kind of burden to their current taxes,” the columnist Eduardo Porter has argued in the New York Times, in one of many such pieces questioning the policy on the grounds of its cost.