In a "This Week" web exclusive, New York Times columnist and Nobel Prize-winning economist Paul Krugman sounded off on Comedy Central host Jon Stewart's dismissive take on minting a platinum trillion dollar coin as a debt ceiling quick fix.

"It is a funny thing. But you want to be funny from a point of view of understanding what the issues are. There's a reason we've gotten to this place," Krugman said of Stewart's "Daily Show" coverage of the platinum coin issue, which Krugman criticized as "intellectual laziness" in a recent blog post. "Obviously neither he nor his staff did even five minutes of looking at the financial blogs. Lots of people think it's a bad idea. Lots of people think it's a good idea. But it's not just, 'Oh, those idiots.'

"Part of the point about Stewart…is that he's funny, but that the show is actually better informed than most of our public discussion. The idea is that the show should be like an especially good episode of the roundtable on 'This Week', but in the form of jokes. But when he just turns it into dumb, "I don't know nothing, but those people look dumb to me," he's ruining his own brand."

Krugman, who appeared on the "This Week" roundtable Sunday, discussed Stewart's platinum coin coverage while answering viewer questions from Facebook for an "All Politics is Social" web segment. See some of Krugman's other responses to questions below.

What do you think Mr. Lew should do first as Secretary of the Treasury?

Krugman: "Wow. I mean, he's not going to have much of a choice, right? He should go in there and slam the table about the debt ceiling. And say, we will give nothing, it's up to you. He should do his Michael Corleone imitation. "My offer to you is nothing."

What do you think of his signature?

Krugman: "I was thinking of putting my own signature up. It's better than that, but not much better. You do book signings, which I've had to do, and if you have got 600 books to sign, you quickly…develop a signature that looks like that… That's pretty silly. That's funnier even than mine. Mine at least looks like I vaguely once along the line tried to pretend I was writing out my name. He's just given up."

Have you ever been wrong and did you admit it?

Krugman: "Actually, I've been wrong on a couple of big things. In the nineties, I pooh-poohed the stories about the take off in productivity, and I admitted that. And I've learned something. If there's buzz out there, pay attention even if it's not in the official numbers yet. And I was really wrong about bond markets in 2003. I thought that the clear irresponsibility of the Bush guys would get reflected. Turns out that markets are willing to give the US a lot more rope than I would have imagined. So, sure. And I've admitted them. One of the great things about the blog is I can take some time off, I wouldn't want to waste column space going through everything I got wrong and why I got it wrong, but I can do it on the blog. I think it is important to face up when you have something wrong."