Steven D. Levitt is an economist. But his interest is not in predicting the trend of Gross Domestic Product, or the future of the stock market. Rather, he applies the basic principles and methods of classical economic theory to diverse topics usually not covered by "traditional" economists. The co-author Stephen J. Dubner has compiled the unconventional findings of the "rogue" economist into this very readable book.
For example, the book analyses the reasons for the sudden decline of crime all over the US since 1992. Just a year earlier, sociologists and criminologists had predicted that crime rate would actually go up in the coming years. Yet, what happened was just the opposite. Crime started to decline in 1992, and dropped sharply since 1995. Levitt rejected the typical (and varying) "explanations" given by the same experts who had all along predicted that crime would go up in the same period.
The "rogue" economist attributed the sudden fall in crime across the US to a single event that took place in 1970. The event was that a young unmarried woman became pregnant. At that time, abortion was illegal all over the US. Some lawyers then took this opportunity to contest the existing state laws on abortion. The case went on for years, and in the meantime the young lady gave birth to a child. But in 1973, the court ruled that the state laws that restrict abortion were illegal.