Krugman's Suspicious Change Of Opinion

After having for years criticising Obama, and Congress, for not increasing deficit spending enough, and for that reason being bearish on the U.S. economy, Paul Krugman changes his mind two months before the U.S. election, and says that even without new Keynesian measures, the U.S. economy is about to start to boom really soon, unless the Republicans win and ruin everything with their policies.

While we are all entitled to change our opinions if the facts change or one encounters a persuasive argument against our previous position, it strikes me as suspicious that Krugman changes his mind at this point of time that benefits the candidate he favors.