Piketty's Three Big Mistakes

Matt Rognlie is a fun guy and a very smart guy. An economics doctoral student at Massachusetts Institute of Technology, Rognlie had a blog, but ditched it in favor of writing long comments and e-mails to bloggers (including yours truly). As proof that blogs can be an important part of the research process, Rognlie turned a blog comment into the most biting critique of Thomas Piketty yet produced.