He's also been pretty open about the fact that he views himself as a voice of the left and he's gradually seen himself as more political and less of an academic

He's also been pretty open about the fact that he views himself as a voice of the left and he's gradually seen himself as more political and less of an academic economist. So he's usually not trying to make testable predictions. I recall this being because he feels he has greater political impact that he did as an academic economist. If you're interested, the New Yorker did a fantastic profile of Krugman a year or two ago that covers how he views his writing for the Times [1]. That said, as other posters have pointed out you're wrong about the specific instance of the stimulus. 1. http://www.newyorker.com/reporting/2010/03/01/100301fa_fact_macfarquhar http://www.newyorker.com/reporting/2010/03/01/100301fa_fact_...