Economics is not widely considered to be one of the sexier sciences. The annual Nobel Prize winner in that field never receives as much publicity as his or her compatriots in peace, literature, or physics. But if such slights are based on the notion that economics is dull, or that economists are concerned only with finance itself, Steven D. Levitt will change some minds. In Freakonomics (written with Stephen J. Dubner), Levitt argues that many apparent mysteries of everyday life don"t need to be so mysterious: they could be illuminated and made even more fascinating by asking the right questions and drawing connections. For example, Levitt traces the drop in violent crime rates to a drop in violent criminals and, digging further, to the Roe v. Wade decision that preempted the existence of some people who would be born to poverty and hardship. Elsewhere, by analyzing data gathered from inner-city Chicago drug-dealing gangs, Levitt outlines a corporate structure much like McDonald"s,...