James Q. Wilson and I offer similar criticisms of the economics book that became a best-seller. Wilson writes,

My advice is this: if you find something that intrigues you in Freakonomics, do not rely on the book to give you a full explanation of it. Instead, look up in a college library or on the Internet the articles Levitt has written, and study them. I wish he had assembled these articles and published them as a book. He would have made much less money, but his ideas would have been much clearer and, even in their scholarly form, easier to deal with.

I write,

If readers come away from this book thinking that they have discovered how economics ought to be done, I would indeed consider it a “sad development.” The book is most notable for its willingness to pass off speculative and tentative findings as though they were well-vetted, settled facts.

…For someone steeped in the social sciences, Freakonomics can be a fun and useful read. But if you read just one economics book this year, make it something else.

I challenge the significance of Levitt’s finding that real estate agents in Chicago sell their homes for higher prices than the homes of their clients. He argues that it shows that agents talk their clients into selling at low prices. I offer an alternative hypothesis.

A typical client may or may not be “under the gun” to sell because of a relocation, change in family status, or what have you. Real estate agents on average are more likely to be moving for “trade-up” reasons. When you are trading up, your focus is on getting the highest price. When you are “under the gun,” your focus is on selling as quickly as possible. Perhaps that is what accounts for Levitt’s results.

Concerning the purported link between abortion and crime reduction, Wilson says,

You would never know it from this book, but not only have these claims been criticized but several scholars have offered rival theories.

I would echo that complaint for many of the findings reported in Freakonomics.