Ezra Klein on the Value of Book Reviews

An interesting read:

This is partly a quirk of journalism: Very few outlets will simply allow a writer -- even a renowned one -- to publish an essay on a large subject of their choice. Magazine articles require ledes, color, and interviews, while op-eds constrain you to three paragraphs and a bio line. But that doesn't mean writers don't have long, non-reported ideas on big subjects that they'd prefer not to turn into books. So political publishing has come up with a sneaky compromise: Publications will let you spend pages and pages ostensibly reviewing a book, when what you're really doing is crafting an essay on the book's subject. That way, the piece ostensibly "reports" on an event -- the release of a new book. And since many writers want to expound on foreign policy and the left, Beinart's book, which addressed that precise topic, has proved perfect cover.