I can't dig it up, but Sumner claimed it would not provided NGDP didn't fall (i.e., the fed caused a monetary offset). You'll never guess what happened next.
Not sure if there are any examples. Economists have never been very accurate because of the nature of economic systems. They are complex adaptive systems, which means that they are very sensitive to initial conditions. Because of the inherent unpredictability we have yet to discover an economic policy that works in the long-run.
A better question would be, "what predictions did Krugman make which disagreed with non-Keynesians that turned out right (or wrong)?"
Various ideological enemies of Krugman made these same predictions. All you are really saying is that Krugman, along with everyone else, gets the easy ones right.
Scott Sumner predicted the former as did most of the market monetarists.
Another great Scott Sumner prediction: fiscal austerity hurts if you lack an independent central bank, but not if you don't (directly contradicting new style Keynesians, e.g. Krugman). The results: http://www.themoneyillusion.com/?p=29692
Various ideological enemies of Krugman predicted the housing bubble, and far more clearly than Krugman; Ron Paul, for example, argued against the creation of a housing bubble in 2001. It's hardly clear to me that Krugman even predicted it. From your article: "To fight this recession the Fed needs more than a snapback...Alan Greenspan needs to create a housing bubble to replace the Nasdaq bubble." The wording is ambiguous, but to me it sounds less like a prediction and more like advocacy.
A few years back I was a solid structuralist, but the monetarists have a really good track record of disagreeing with other people and coming out right.
Calling the market monetarists ideological enemies of Krugman seems like an exaggeration. He's linked to and cited them favorably a lot (although he has basic disagreements with them.)
> Various ideological enemies of Krugman predicted the housing bubble, and far more clearly than Krugman; Ron Paul, for example, argued against the creation of a housing bubble in 2001.
I'm not qualified to adjudicate between Krugman and the market monetarists, but I feel it is important to realise that many (and many prominent) people did fail to make these predictions, and essentially all of them have kept their jobs and their status.
