A look at land-use zoning in Chicago suggests you have to be a bit more specific.
In the run-up to the 2016 presidential campaign, Donald Trump told The New York Times that America’s urban centers are some of the “most dangerous,” crime-filled places in the world. Even though experts were quick to point out that violent crime has actually declined in all but a handful of America’s largest cities and urban areas, the view of cities as dense, dirty, and dangerous and suburbs as spread out, pastoral, and safe has long pervaded American culture.
But this begs a deeper question about the connection between crime and the characteristics of urban neighborhoods. Countless criminology studies show that high levels of violent crime are concentrated in a relatively small number geographic hot spots, but there are also aspects of urban life and communities that deter crime. Jane Jacobs long ago told us that dense, walkable, mixed-use urban neighborhoods with lots of ”eyes on the street” are a strategy for combatting urban crime. But there are features—from abandoned buildings to bars and nightclubs—that may make crime worse.
A new study published in the Journal of Urban Economics by Tate Twinam of the University of Washington takes a detailed look at the connection between these neighborhood characteristics and urban crime in Chicago, a city that has witnessed a much-publicized recent rise in murder and violent crime. Crime has cost Chicago a great deal, as the study points out. In 2013, the city spent over $1.3 billion on policing; the costs of robberies set its citizens back another $500 million.
The study develops very detailed data on crime and a wealth of neighborhood characteristics. For crime, it identifies the location of every instance of robbery, assault, and battery that took place in Chicago between 2008 and 2013. It compares this to the walkability of neighborhoods based on Walkscore data, and demographic information on income, poverty, public assistance, race, and ethnicity from the U.S. Census. It also looks at the connection between crime and the location of different types of commercial land uses such as restaurants, liquor stores, and late-night bars.
The study pinpoints crimes that occurred within specific areas—circles of roughly 150 square feet—and maps them against land use in the immediate vicinity. The researchers look at crime in pairs of streets with different mixes of commercial activity and different patterns of land use.
The study generates several important conclusions for our understanding of the connections between neighborhood characteristics and urban crime and what cities can do about it.
At first glance, commercial activity appears to lead to higher rates of crime. And this is particularly the case in walkable areas. But this effect declines and ultimately reverses at higher densities. A shift from residential to commercial use is associated with roughly 1.2 more robberies and 2.5 more assaults per 1,000 residents. Given that overall robbery and assault rates are 2.6 and 7.3 per 1,000 residents, respectively, this suggests a strong relationship between crime and commercial land use activities.
But this connection between crime and commercial activity can mostly be attributed to restaurants, bars, and liquor stores, and especially between 2 a.m. and 6 a.m., when late-hour bars are open. In statistical wonk-speak, an additional late-hour bar yields a 0.19 standard deviation increase in the assault rate, while a liquor store yields 0.31 standard deviation increase in robbery rates and a 0.46 standard deviation increase in the assault rate.
The study has two clear implications for helping reduce crime in urban areas. Crime is not only concentrated spatially, its concentration is pretty stable over time. That clustering seems to justify focusing policing resources on hot-spots—particularly in areas with high concentrations of liquor stores, bars, and after-hours clubs, and especially on weekends.
To sort out neighborhood effects, the study also looks at historical land use and historical zoning going back to the 1920s and 1930s, as well as historical data on demographics and gang activity of neighborhoods going back decades. (Interestingly, the study finds that historical zoning had a strong effect on the composition and mix of current land use and economic activity.)
More broadly, the study suggests that efforts to promote residential density and mixed-use development may well help to deter crime, in addition to potentially taking pressure off housing costs and developing a more vibrant, walkable city.