There’s an interesting article by Jim Manzi in the most recent issue of the City Journal. In it, he addresses the weaknesses of empirical research in the social sciences, a problem he attributes to the greater “causal density” of questions concerning human behavior. Because of he complexity and number of potential causes for an outcome, it is extremely difficult to conduct randomized field trials that isolate the cause to be tested.

 Manzi begins his article by referring back to the debate about the stimulus package. Noting that Nobel laureates lined up on both sides of the question, he writes that “[f]ierce debates can be found in frontier areas of all the sciences, of course, but this was as if, on the night before the Apollo moon launch, half of the world’s Nobel laureates in physics were asserting that rockets couldn’t reach the moon and the other half were saying that they could.” The only thing that could be said for sure about the stimulus is that, however it turned out, “several Nobelists would be wrong about it.”