Today the Daily News has an interesting article about the Philadelphia Housing Authority, and its demolition of high-rise towers with lower density homes. The article sort of talks about this, but, one of the main points that PHA and so many others make is that when you knock down big projects, crime decreases. And, the article cites housing project after housing project, where crime goes down:

At the six sites that have been demolished and rebuilt using new design concepts championed by PHA Executive Director Carl R. Greene, the total number of major crimes has plummeted 63 percent from 1999, Greene's first full year here, to 2007. In contrast, the number of major crimes jumped 65 percent at all 45 PHA-run public-housing developments during the same period.

Greene, who studied the design ideas of New Urbanism, has advocated mixed-income developments in which residents have their own private yards and where neighborhood streets pass through the site, integrating it with the surrounding area rather than isolating it.

.....

...Cambridge Plaza, where major crimes fell 69 percent from 16 in 1999 to five last year. Or to Greater Grays Ferry Estates, formerly Tasker Homes, which saw a drop of 73 percent, from 75 in 1999 to 20 last year.

We are led to believe that architecture solves crime. But, what is missing from the statistics above is pretty obvious: we know the number of incidents of crime dropped, but, how many less people live there? Is the drop simply because there are far less people? We never really get before and after population numbers except for one: The big, bad, Richard Allen homes.

And, what do we find, but:

Richard Allen Homes, adjacent to Cambridge Plaza, opened in 1942 with 1,324 low-rise units. It was notorious as a crime-infested project from the 1960s up until the first phase of its demolition in 1997. Today, the development has about a third of the number of units, and subsequently, fewer people living there. Its 408 units consist of a mix of brand-new homes, rehabbed ones and apartments in a senior building.

With the renovation and the fewer units, the number of major crimes at Richard Allen has dropped from 32 in 1999 to 11 last year.

Dorn acknowledged that crime has gone down at some sites because fewer people now live in them, but contends the issue has more to do with population density and the architecture of the sites.

OK, so, you take away two-thirds of the people of Richard Allen (and in fact, probably take away more than 2/3rds of the original residents, given many projects become mixed income), and you lose.... 2/3rds of the crime. Not to be a jerk, but doesn't that sort of imply that, at the end of the day, as absolutely crappy and terrible as these huge projects were, crime might not have been caused by architecture, but instead by the fact that most people in PHA homes are desperately poor- with a median income of $11,000 a year? (And by the way, with a PHA waiting list that would stretch for miles, where do people go when 2/3rds of them are told to move out? There is a finite supply of PHA housing, after all.)

Aside from the issue of wondering exactly where people magically go when they are moved out of high-rises, not many people will be shedding tears when thinking about the demolition of Richard Allen, MLK and the rest of the high-rises. A number of reports suggest that it improves home values in neighborhoods surrounding the projects. Would the boom that is happening in many of the surrounding neighborhoods still happen if these projects stood? I doubt it.

There are other reasons we want to mix incomes: urban economists often talk about the value of networking, of increasing social capital and employment, etc. There is a whole body of research on whether or not that is true, and I will leave it to urban studies people to weigh-in. Either way, I think many people would agree that whether it causes crime or not, shoving a bunch of poor people in enormous apartment complexes doesn't feel particularly like a society that we want to take place in.

However, the biggest factor causing crime in housing projects is entrenched, generational poverty, and everything that comes from that. So while we can undo our past urban policy mistakes, it would be a real mistake to think that poverty is 'solved' by knocking down a few high-rises, and bringing in some working to middle-class residents among them.