We liked Tina Rosenberg's book on Eastern Europe's transition from communism, but her latest contribution to the New York Times's Opinionator blog is quite an eye-roller. "The Power of Talking to Your Baby," it's called, but this isn't one of those first-person mommy blogs. Instead, it appears under the heading "FIXES," a series that "looks at solutions to social problems and why they work."

Actually, there's no evidence that the "solution" works. As Rosenberg admits, "it is about...