A lie can go halfway 'round the world before truth gets its boots on.
Steven Malanga writes in "Where Freakonomics Errs:"
But in economics, new theories based on innovative research are almost immediately tested to see if they can be replicated, and in Levitt’s case what quickly emerged were counterstudies that questioned his methods and conclusions. Professor Ted Joyce of City University of New York found that incidents of homicide by perpetrators in age groups too old to have been affected by legalized abortion declined faster than murders by younger perps. John Lott of the American Enterprise Institute and John Whitley of Adelaide University in Australia noted that research on the legalization of abortion suggested that it actually increased illegitimate births and single-parent families. They concluded that rather than decrease crime, legalized abortion probably contributed slightly to its increase.
Levitt has addressed some of these criticisms in academic journals, though not convincingly, to my mind. But in Freakonomics, he completely ignores this counterevidence and presents his own work as if it’s Scripture. Only a few reviewers, most notably the eminent sociologist James Q. Wilson in Commentary, have noted the way the book merely disregards the work of others.
But the flaws in Levitt’s notion of what caused crime to fall go beyond his theory of abortion. In Freakonomics he also dismisses the idea that innovative policing methods of the type that New York instituted during the Giuliani years had any effect on crime. This idea has been particularly attractive to reviewers of the book, prompting Lowenstein in the Times to crow that “[w]hile all the world was congratulating Rudolph W. Giuliani for reducing violent crime . . . the authors demonstrate that Hizzoner probably had little to do with it.”
Levitt bases this conclusion not only on his work on abortion but on another study he’s done, which attempts to correlate declines in crime with the expansion of a city’s police force. Looking at data from 1970 through 1992, Levitt concludes that adding to the size of your police force probably accounted for about 10 percent of the 1990s drop in crime. With that in mind, he rejects the idea that New York’s policing methods helped rein in crime because, once one adjusts for the growth in Gotham’s force, which Levitt says increased by 45 percent, the city’s reduction in crime is no greater than that of Los Angeles, a city that never incorporated the “broken windows” policing that Giuliani championed.
But there are serious questions about Levitt’s work here. For one thing, once you adjust the growth in New York’s police force for the expansion of its population during the 1990s and then compare it with per capita police rates in other cities (as even Levitt does in his other work), the numbers tell a different story. New York’s police force grew by 18 percent per capita during the 1990s, according to an FBI study, “Police in Large Cities.” This put the city behind police force increases in Newark, and in line with or slightly ahead of gains in cities like Baltimore, where the size of the force relative to the population rose by 20 percent, in Philadelphia by 13 percent, St. Louis by 10 percent, and Chicago by 9 percent.
What’s startling about this list is how little these increases in staffing paid off for most of these cities during the 1990s. While New York’s violent crime rate declined by 65 percent in the 1990s, most of these other cities saw only small decreases in crime, and in a few cases violent crime actually rose. Chicago, for one, ultimately passed New York as the place with the highest total of murders per year, even though Chicago’s population is only 38 percent of New York’s. [more}