In 2003, when the debt was less than half what it is today, he wrote, “We’re looking at a fiscal crisis that will drive interest rates sky-high . . . But what’s really scary — what makes a fixed-rate mortgage seem like such a good idea — is the looming threat to the federal government’s solvency . . . How will the train wreck play itself out? . . . My prediction is that politicians will eventually be tempted to resolve the crisis the way irresponsible governments usually do: by printing money, both to pay current bills and to inflate away debt.”

Inflation to pay current bills, a reference to hyperinflation, is exactly what he would later ridicule Kinsley for worrying about.

In 1996, Krugman (who, as Wall Street Journal blogger James Taranto never tires of reminding us, is a former Enron adviser) said Social Security has a “Ponzi-game aspect in which each generation takes out more than it put in.” Last year he said it “is and always has been mainly a pay-as-you-go system, which is nothing like a classic Ponzi scheme.”

Of unemployment benefits, Krugman wrote in his textbook that “The drawback to this generosity is that it reduces a worker’s incentive to quickly find a new job.” Later he ridiculed Sen. Jon Kyl (R-Ariz.) as “bizarre” for saying, “Continuing to pay people unemployment compensation is a disincentive for them to seek new work.”