The Atlantic article on crime and the spread of Section 8 vouchers to the suburbs which in turn also spreads crime was compelling though not entirely convincing. For those who believe that you can take the poor out of the crime ghettos but not the crime out of the poor ghettos this article provided the ammunition.
On a theoretical level the idea is that as more poor people with Section 8 vouchers move out of the inner city and as they begin locate closely to one another again they form a new pocket of crime. While one or two househoulds with a Section 8 voucher in a suburb may not result in an increase in crime, maybe ten or more households might be sufficient to increase crime because it is more likely that at least one or two households have a criminal past and are more likely to vicitimize one another and others in the new neighborhood. I actually have a strong prior on this though it is only theoretical.
This paper by Jeff Kling and Jens Ludwig ("Is Crime Contagious") uses data from MTO randomization/demonstration program finds results that I would characterize as mixed. I called MTO a demonstration program because the HUD site indicates this is what it was although the analysts who ran it call it a randomized trial. I hestitate to call this a randomized trial because if memory serves they had difficulty recruiting households to participate.
The authors conclude:
Our results are not consistent with the idea that contagion explains as much of the across neighborhood variation in violent crime rates as previous research suggests. We do not find any statistically significant evidence that MTO participants are arrested for violent crime more often in communities with higher violent crime rates. Our estimates enable us to rule out very large contagion effects, but not more modest associations. This general finding holds for our full sample of MTO youth and adults as well as for sub-groups defined by gender and age, and it also holds when we simultaneously instrument for neighborhood racial segregation or poverty rates.
I don't know how this translates into rising "local" crime rates that are more of interest to police in the Atlantic article. The article is concerned that crime rates rise in suburbs and the Kling and Ludwig do not test that crime rates rise in the neighborhoods in which the MTO participants move into. The definition of "neighborhood" is one difficulty althought it may be possible to test for the significance of whether MTO participants are arrested for violent crime more often in communitites with lower violent crime rates. It is possible that there was not enough variation in the data to perform this test.