James Q. Wilson's interesting take on what is behind falling crime rates: culture

The Wall Street Journal over the weekend published this great essay by renown social scientist James Q. Wilson under the headline "Hard Times, Fewer Crimes." The piece provides an extended and very interesting set of explanations for the wonderful modern declines in crime rates in the United States. The piece demands a full read, and here are just a few parts of Wilson's assessments:

[W]e have little reason to ascribe the recent crime decline to jobs, the labor market or consumer sentiment.  The question remains: Why is the crime rate falling?

One obvious answer is that many more people are in prison than in the past.  Experts differ on the size of the effect, but I think that William Spelman and Steven Levitt have it about right in believing that greater incarceration can explain about one-quarter or more of the crime decline.  Yes, many thoughtful observers think that we put too many offenders in prison for too long. For some criminals, such as low-level drug dealers and former inmates returned to prison for parole violations, that may be so. But it's true nevertheless that when prisoners are kept off the street, they can attack only one another, not you or your family.

Imprisonment's crime-reduction effect helps to explain why the burglary, car-theft and robbery rates are lower in the U.S. than in England.  The difference results not from the willingness to send convicted offenders to prison, which is about the same in both countries, but in how long America keeps them behind bars.  For the same offense, you will spend more time in prison here than in England. Still, prison can't be the sole reason for the recent crime drop in this country: Canada has seen roughly the same decline in crime, but its imprisonment rate has been relatively flat for at least two decades.

Another possible reason for reduced crime is that potential victims may have become better at protecting themselves by equipping their homes with burglar alarms, putting extra locks on their cars and moving into safer buildings or even safer neighborhoods.  We have only the faintest idea, however, about how common these trends are or what effects on crime they may have.

Policing has become more disciplined over the last two decades; these days, it tends to be driven by the desire to reduce crime, rather than simply to maximize arrests, and that shift has reduced crime rates.  One of the most important innovations is what has been called hot-spot policing. The great majority of crimes tend to occur in the same places. Put active police resources in those areas instead of telling officers to drive around waiting for 911 calls, and you can bring down crime....

There may also be a medical reason for the decline in crime.  For decades, doctors have known that children with lots of lead in their blood are much more likely to be aggressive, violent and delinquent.... Tests have shown that the amount of lead in Americans' blood fell by four-fifths between 1975 and 1991.  A 2007 study by the economist Jessica Wolpaw Reyes contended that the reduction in gasoline lead produced more than half of the decline in violent crime during the 1990s in the U.S. and might bring about greater declines in the future.  Another economist, Rick Nevin, has made the same argument for other nations.

Another shift that has probably helped to bring down crime is the decrease in heavy cocaine use in many states....

Blacks still constitute the core of America's crime problem.  But the African-American crime rate, too, has been falling, probably because of the same non-economic factors behind falling crime in general: imprisonment, policing, environmental changes and less cocaine abuse....

John Donohue and Steven Levitt have advanced an additional explanation for the reduction in black crime: the legalization of abortion, which resulted in black children's never being born into circumstances that would have made them likelier to become criminals.  I have ignored that explanation because it remains a strongly contested finding, challenged by two economists at the Federal Reserve Bank of Boston and by various academics.

At the deepest level, many of these shifts, taken together, suggest that crime in the United States is falling — even through the greatest economic downturn since the Great Depression — because of a big improvement in the culture.  The cultural argument may strike some as vague, but writers have relied on it in the past to explain both the Great Depression's fall in crime and the explosion of crime during the sixties. In the first period, on this view, people took self-control seriously; in the second, self-expression — at society's cost — became more prevalent.  It is a plausible case.

Culture creates a problem for social scientists like me, however.  We do not know how to study it in a way that produces hard numbers and testable theories.  Culture is the realm of novelists and biographers, not of data-driven social scientists.  But we can take some comfort, perhaps, in reflecting that identifying the likely causes of the crime decline is even more important than precisely measuring it.

A few recent related posts on how to account for still-dropping crime rates in the US:

• Wonderfully puzzling violent crime rate continue to decline (despite NFL lockout)
• Making the full-throated case for the notion that more Internet = less crime
• Another account of the crime rate's changing realities: blame the baby boomers