Freakonomics is an invitation to look at the world through the eyes of an economist. The book follows a New York Times Magazine article co-author Steven Dubner wrote profiling “rogue economist” Steven Levitt, who established himself by applying economic reasoning — most prominently, a careful look at incentives — to uncommon problems.
The approach lies somewhere in an amorphous nexus surrounding economics, sociology, criminology, and data analysis. Whatever it is, since its original publication in 2005, Freakonomics has spawned an expanded edition, sequel, radio show, podcast, blog, and documentary film. Why did this book draw so much attention? And what is a mathematician to make of it?
The book is more about an approach than any particular topic. Indeed, the topics of the chapters are largely unrelated. The only common theme is the reasoning employed, whereby the authors take a careful look at precisely how the relevant players in a social structure are motivated. A simple but typical example is the observation that a real estate agent selling your home is not really incentivized to push for a better offer because the marginal increase in the agent’s commission is far less compelling to the agent than is the much greater marginal increase in your revenue. The authors take seriously the problem of defending their arguments with data — in this case, by examining how the agents’ behavior changes when selling their own homes.
The narrative elegantly interweaves data analysis with broad themes and anecdotes, making for a popularly accessible book with some real ideas. The chapters are also titled with mysterious questions (“How is the Ku Klux Klan Like a Group of Real Estate Agents?” “Why Do Drug Dealers Still Live with Their Moms?”) to make it impossible to stop reading.
The book has no problem being provocative. Among the more notorious arguments in the book is the claim that a sharp drop in the U.S. crime rate in the 1990s was a consequence of would-be criminals having never been born due to the legalization of abortion. The book shines by refusing to acknowledge the political baggage such a claim will carry until well after the argument is made. The authors credibly address the problem by taking it apart, offering some data, and making a case. You may or may not agree with the conclusions, but either way there is value in considering the approach.
The arguments exemplify what teachers often mean by critical thinking. This is an honest effort in problem-solving, and that is where the mathematically-minded reader will find engagement. This is a book for the masses, however, and as such the mathematics is not meant to be very deep. Most of the arguments are drawn from elementary summary statistics, although there is an earnest discussion of regression analysis in the final chapter, where tying baby-naming trends to socio-economic status is used to explore the classic correlation/causation conundrum. The discriminating mathematical reader probably will not be impressed by many of the techniques employed and will have to look to the references for meatier analysis, but the beginnings of some engaging discussions are present.
The revised edition features a host of bonus material, including Dubner’s original New York Times Magazine profile of Levitt, excerpts from the Freakonomics blog, and a “Q&A” section (reminiscent of a magazine letters page). This extra material includes further commentary on the topics from the book, discussion of reactions to the book itself, and some new ideas. Fans of the first edition might consider a look at this edition.
There is also an extensive notes section that includes references, commentary on sources, and some miscellaneous tangents. The attention paid to the references is important in a work like this, so it scores some points there.
We mathy folks like well-posed problems with logical arguments leading to a clear solution. That is not how societal issues are always addressed in the popular press and it is refreshing to see a real effort made to offer some innovative analysis. Freakonomics can be simultaneously enlightening, fun, and frustrating, but it is certainly a valuable read to anyone who thinks deeply about interpreting the world.
Bill Wood is a mathematician, board game enthusiast, lousy disc golf player, and impending faculty member at the University of Northern Iowa.