From the Berkeley Blog:
In a recent Brookings Institution paper, Elizabeth Kneebone and Stephen Raphael looked at violent and property crime rates in the United States from 1990 to 2008 in the 100 largest metropolitan areas of the country, areas where two out of three Americans live — urban conglomerations that range in size from Ogden, UT, and Modesto, CA, to Chicago and New York City. The authors describe the trends in crime separately for the central cities versus the suburbs of those regions.
On average, the rate of violent crime – the risk of being victimized by murder, robbery, assault, rape and the like –dropped about 30 percent in the center cities of metropolitan areas and by only about 7 percent in their suburbs. Most dramatically, rates of violent crime dropped in the center cities of the New York region by about 75% and of the Chicago region by 80%. The center cities still have higher rates of violent crime than suburbs do, but instead of being about triple the suburban rates as they were in 1990, they are now less than double the suburban ones.
[t]he authors’ analysis shows that a growing Hispanic population is associated with a decline in violent and property crime.
That is, violent crime became a particularly big-city phenomenon about 40 years ago and now has become less so in the last 20 years.
Demographic and economic factors do not explain the trends:
Perhaps there’s another explanation for the widening and closing of city-suburban-rural differences in violent crime. Kneebone and Raphael tried to explain the recent closing of the gap by looking at the demographic and economic features of communities, but those did not account for the pattern. Something else is going on.