Last week, the FBI reported crime rates in the United States fell in 2010. These declines continue a downward trajectory that began in the 1990s and continued even as many worried the worst economic downturn since the Great Depression might lead to a spike in criminal behavior.
This is all good news, but behind the numbers are some surprises that challenge a few conventional assumptions about the causes of crime — and we’re not just talking about the economy’s role, or lack thereof. Crime is often associated with poverty, race, immigration, or big-city life, but today those relationships are not as predictable as many believe. Our metropolitan areas became safer over the last two decades even as they became more ethnically, racially, and economically diverse.
In a recent study we found the nation's 100 largest metropolitan areas are indeed safer today than in 1990, but not all communities shared equally in these gains. What places benefitted the most? Big cities — denser, more urbanized central cities that tend to be poorer, more diverse, and had higher crime rates to begin with. These places saw both violent and property crime rates fall faster than in the surrounding suburbs, narrowing the gap between cities and suburbs.
Crime trends within the Boston region follow a similar trajectory, with one exception. Taken together, the cities of Boston and Cambridge benefitted the most from declining crime, as violent crimes like murder, rape, and aggravated assault dropped by 55 percent and property crimes like burglary, larceny, and motor vehicle theft fell by more than 60 percent. At the same time, suburban property crime fell (more slowly but still significantly) by 27 percent. But the suburban violent crime rate actually crept up slightly (5 percent) over this time period.
Why did suburban violent crime increase in the Boston area? Many factors influence these trends, but our study shows that the uptick is likely not related to demographics.
Amidst falling crime rates and increasing diversity, the relationships between crime and things like the share of residents who are poor, African American, Hispanic, or foreign-born weakened significantly. And in suburban communities that experienced slight increases in violent crime — similar to the Boston-Cambridge region — changing demographics did not explain those changes at all.
What does this all mean? In general, these trends are great news for the 100 largest metro areas, which are home to two-thirds of the nation's population and markedly safer than 20 years ago. It's especially good news for the cities that make up the hubs of these regions, since they benefitted most from these trends. Dramatic crime declines in these places serve to make cities more attractive places to work, live, and play, which could mean good things for property values and perhaps even slow down the urge to sprawl away from the urban core.
Moreover, city and suburban crime trends tend to move together over time. Couple that with narrowing of the gap between city and suburban crime rates, and it underscores the metropolitan nature of these issues.
Crime is not just an urban challenge, but one that's shared across cities and suburbs in a region. Thinking of these issues from a metropolitan perspective can open up opportunities for collaboration and information-sharing across communities on lessons learned and strategies that show promise in similar neighborhoods or regions (opportunities that could be particularly beneficial to communities where crime declines have stalled or lost ground). As metro areas work to understand these trends and reduce crime, our findings also show that policymakers, communities, and law enforcement agencies must increasingly look beyond demographics to understand the large shifts in crime that have taken place since the 1990s. When trying to solve an issue as complicated and multifaceted as what drives changes in crime, knowing what is not a cause is an important step toward understanding what is.
Steven Raphael is a professor of public policy at the University of California, Berkeley and Elizabeth Kneebone is a senior research associate at the Brookings Institution Metropolitan Policy Program. They are the authors of the report, City and Suburban Crime Trends in Metropolitan America