"So if he wants to joke about it, that's fine, that's his right. But he has not actually offered any response at all to my criticisms," added Krugman, a relentless critic of both Ryan and the journalists who lionize him as a deficit hawk.
A spokesman for Ryan declined to comment.
The Princeton professor and Nobel Prize-winning economist argued that the Ryan budget's deficit-reduction capacity amounts to "empty boasts" in its promise to offset large tax cuts by closing unspecified loopholes. Compounding that problem, the economist noted, is how Ryan has vowed to oppose new taxes on capital gains.
"So he's just claiming that he can find trillions of dollars from no specified source and in fact has ruled out the only place you could find it," Krugman said.
Because his criticisms have failed to penetrate the establishment media, Krugman has taken to attacking reporters and pundits who portray the GOP congressman as a scrupulous budget fix-it man.
"I have to admit it's pretty amazing how robust the Ryanology continues to be, despite the fact that every time he produces an allegedly wonkish budget document it turns out to be totally full of holes," Krugman said. "He's become this beloved symbol of the alleged responsible wing of the Republican Party that no one wants to go after him.... I had thought that in some of the recent reporting people were getting a little bit more realistic about what was going on with him, but maybe not."