By Michael Kennedy

Steven Levitt and Stephen Dubner are at it again. Their first book, “Freakonomics,” sold over four million copies; its follow-up is dubbed “SuperFreakonomics.”
The authors explain in the preface that they have waited four years to write the follow-up book, ensuring that all the stories were good enough. The new book, they conclude “is easily better than the first.” While that statement is certainly open to debate, SuperFreakonomics is certainly a worthy successor.
SuperFreakonomics is more of the same for Levitt and Dubner. They seem to continue to take pride in turning readers’ worlds upside down. “Most of the stories fall into one of two categories: things you always thought you knew but didn’t; and things you never knew you wanted to know but do,” they said in their preface.
In the first chapter, the authors explore the world of prostitution, from the streets of Chicago to the high-priced world of escorts. They realize that any prostitute follows the laws of economics, their price varying based on clientele, acts performed, location and a number of other factors.
In a more disturbing chapter, the authors explain why doctors are actually quite bad about washing their hands—washing their hands only nine percent as often as they should. But, like all individuals, doctors respond to incentives. And the best way to get them to wash their hands is to give them something they appreciate, like showing them how much bacteria is actually on their hands.
The authors also show how an unfortunate birthday can disadvantage you for life. Unfortunately, Malcolm Gladwell had written extensively about that same study in his latest book, “Outliers,” a point the authors concede in a footnote. They were going to write a chapter about it, but reduced it to a few paragraphs for that very reason. Perhaps they shouldn’t have waited four years after all.
SuperFreakonomics is a page-turner, and Levitt and Dubner have delivered a fun book which will surely be another hit. Some of the novelty has worn-off since their first book, and this research isn’t nearly as revolutionary as their prior work, but SuperFreakonomics is a must-read for anyone wanting to explore the hidden side of things.