Correcting Krugman - It's been said by somebody that you shouldn't teach a pig to sing since you just waste your time and annoy the pig. The same object lesson in futility applies to former Enron advisor Paul Krugman who never admits fault under any circumstances. That said, both Paul Ryan and Megan McArdle have pushed back against the NYT columnist. Will the little guy admit he's been incorrect and/or lying? Don't hold your breath. McArdle: "Krugman is wrong on Ryan and the CBO."