It's annoying that most premier leftish or left-leaning pundits never really argue for anything–they explain. They don't explain the cogency of their view either. They explain different sides in a debate without making an argument for which side is the correct one. Go read just about any column from E.J.Dionne and you'll know what I mean.
This has really never been the case with Krugman. Here's an excellent example:
Arguments From Authority
A quick note on David Brooks’s column today. I have no idea what he’s talking about when he says,
The Demand Siders don’t have a good explanation for the past two years
Funny, I thought we had a perfectly good explanation: severe downturn in demand from the financial crisis, and a stimulus which we warned from the beginning wasn’t nearly big enough. And as I’ve been trying to point out, events have strongly confirmed a demand-side view of the world.
But there’s something else in David’s column, which I see a lot: the argument that because a lot of important people believe something, it must make sense:
Moreover, the Demand Siders write as if everybody who disagrees with them is immoral or a moron. But, in fact, many prize-festooned economists do not support another stimulus. Most European leaders and central bankers think it’s time to begin reducing debt, not increasing it — as do many economists at the international economic institutions. Are you sure your theorists are right and theirs are wrong?
Yes, I am. It’s called looking at the evidence. I’ve looked hard at the arguments the Pain Caucus is making, the evidence that supposedly supports their case — and there’s no there there.
And you just have to wonder how it’s possible to have lived through the last ten years and still imagine that because a lot of Serious People believe something, you should believe it too. Iraq? Housing bubble? Inflation? (It’s worth remembering that Trichet actually raised rates in June 2008, because he believed that inflation — not the financial crisis — was the big threat facing Europe.)
The moral I’ve taken from recent years isn’t Be Humble — it’s Question Authority. And you should too.
It's especially rare for columnists to address each other by name. Brooks, in his usual dichotomous fashion, has set up a false bifurcation (here are two sides, whoa, this one is crazy wrong–and it's adherents make weak arguments–therefore this other one is the one we should go for). For an entertaining comment on Brooks' dichotomizing, read this at the Daily Kos.
Krugman doesn't call him on that, rather he calls him on his total reliance on a limited set of authorities (and his disregard for the arguments Krugman and others have made). Without judging the efficacy of Krugman's claims, I would say that this is a textbook case of good criticism: find the key inference someone makes–in this case an argument from authority–and raise a meaningful question about it.