No Krugman is habitually wrong 24/7.
As I understand it, he has great insight into the factors governing international business siting decisions (the basis for his Nobel Prize). If he's making pronouncements on that one, narrow topic, I'll sit up and attend to what he's saying. Otherwise he's just another academician, who having become the world's expert on one little topic though years of work, fancies he's the world's expert on his whole discipline, and now, even on things in tangentially related areas.