There is a thing called stagflation...
Anyways, in the interview Krugman says we got a "$20-trillion-a-year economy," "20, 25% of the economy is going to be shut down for an extended period," the "[disaster relief bill] might end up being $4 trillion or $5 trillion" instead of the "$2 trillion", which is "not enough money"... I'm not sure his math is adding up with reality. The article was written Apr 2, but the month isn't even over yet and the small business funds are (almost?) depleted, the $1200 check is done, the paycheck protection is (almost?) depleted, and I'm not sure what else I'm missing. The going rate looks more like $2 trillion (on the low end) every couple months, so unless he thinks everything's going to be resolved in under a couple more months, I'm not sure how the bill is going to stop at just $4 or $5 trillion. The odds that this year's economy (I'm assuming he means GDP) hitting $20 trillion (or 75% of that) also isn't a sure bet.
Then at the end of the article, he says Denmark's government is doing a good job by picking up 75% of its tab... Something tells me there's a reason why in any previous economic bumps (minor and major) in history, the option of having the government take over the tab was not considered the obvious easy decision, much less purposely shutting down the majority of the economy.