Most Popular Books by Steven D Levitt

The legendary bestseller that made millions look at the world in a radically different way returns in a new edition, now including an exclusive discussion between the authors and bestselling professor of psychology Angela Duckworth. Which is more dangerous, a gun or a swimming pool? Which should be feared more: snakes or french fries? Why do sumo wrestlers cheat? In this groundbreaking book, leading economist Steven Levitt—Professor of Economics at the University of Chicago and winner of the American Economic Association’s John Bates Clark medal for the economist under 40 who has made the greatest contribution to the discipline—reveals that the answers. Joined by acclaimed author and podcast host Stephen J. Dubner, Levitt presents a brilliant—and brilliantly entertaining—account of how incentives of the most hidden sort drive behavior in ways that turn conventional wisdom on its head.

Previous empirical studies have typically uncovered little evidence that police reduce crime. One problem with those studies is a failure to adequately deal with the simultaneity between police and crime: while police may or may not reduce crime, there is little doubt that expenditures on police forces are an increasing function of the crime rate. In this study, the timing of mayoral and gubernatorial elections is used to identify the effect of police on crime. This paper first demonstrates that increases in the size of police forces disproportionately occur in mayoral and gubernatorial election years, a relationship that had previously gone undocumented. After controlling for changes in government spending on other social programs, there is little reason to think that elections will be otherwise correlated with crime, making elections ideal instruments. Using a panel of large U.S. cities from 1970-1992, police are shown to reduce crime for six of the seven crime categories examined. Each additional police officer is estimated to eliminate eight to ten serious crimes. Existing estimates of the costs of crime suggest that the social benefit of reduced crime is approximately $100,000 per officer per year, implying that the current number of police is below the optimal level.

Over the last two decades the punitiveness of the juvenile justice system has declined" substantially relative to the adult courts. During that same time period juvenile violent crime" rates have grown almost twice as quickly as adult crime rates. This paper examines the degree to" which those two empirical observations are related, finding that changes in relative punishments" can account for 60 percent of the differential growth rates in juvenile and adult violent crime" between 1978 and 1993. Juvenile offenders appear to be at least as responsive to criminal" sanctions as adults. Moreover, sharp changes in criminal involvement with the transition from" the juvenile to the adult court suggest that deterrence, rather than simply incapacitation important role. There does not, however, appear to be a strong relationship between the" punitiveness of the juvenile justice system that a cohort faces and the extent of criminal" involvement for that cohort later in life.