Too Many Broken Windows or Too Few Immigrants?

As homicides soar in a number of East (and West) Coast cities, criminologists and police experts are divided on how to explain this dramatic turn around to what had been a nearly universal decade of crime decline between 1994 and 2004. As profiled in a recent Yahoo story, one emerging explanation focuses on the failure of these cities to adopt the right kinds of policing strategies, the other emphasizes the role of immigrants in defusing violence within low income parts of the city.

One theory is that police in these particular cities (Philadelphia, Baltimore, Newark) missed out on the revolution in police technique carried out in the 1990s in various cities (especially New York). Some adherents of this view emphasize the popular Broken Windows theory that when police crack down on a minor misbehavior (from public urination to marijuana use) they send signals through the community that results in fewer serious crimes.

The other major theory, promoted by criminologists Robert Sampson of Harvard and Larry Sherman of Penn emphasizes the relative absence of immigrants in these same cities. Sherman has offered the most complete explanation (although he acknowledges it is untested and incomplete):

"Cities that have heavily concentrated and segregated African-American poverty are the places that have increases in homicide," Sherman said. "The places that have lots of immigration tend not to have nearly as much segregation and isolation" of poor blacks.

Sherman acknowledges the theory is evolving and unproven.

"The fundamental driver of the homicide rate is honor killings among young black men," Sherman said. "What is it about immigration that tends to tone it down? I don't think we know the answer to it."

He said immigrants "change the spirit" of a community and affect the way young black men in poor areas relate to each other.

"It seems a plausible way to account for the big difference in the trajectory of homicides" in stagnant cities versus ones with lots of immigration, he said.

The percentage of foreign-born residents is 11 percent in Philadelphia, compared with 22 percent in Chicago, 37 percent in New York and 40 percent in Los Angeles, according to 2005 census figures.

It is noteworthy that these theories point in very different policy directions. Fixing more "Broken Windows" would mean more "governing through crime." Getting more immigrants, many of whom are illegal, into places like Newark and Philadelphia would be mean less "governing through crime."