A recent article on the site Books and Ideas article on displacements/evictions of inner city poor referenced an important article by a University of Wisconsin-Madison sociology professor on the same subject. The article, On the Run: Wanted Men in a Philadelphia Ghetto by Alice Goffman should be required reading for anyone interested in the plight of American inner-cities and the urban (and increasingly suburban) poor.
So why don't we see more affordable housing? The answer is that, when municipalities do site redevelopments, predominantly what they are interested in is maximizing tax revenues in the long term. That is why they are willing to use tools like Tax Increment Financing (TIF) or tax abatements as a means of making redevelopment more attractive. As Harvey Molotch observed years ago, cities are growth machines. This means that, it costs more money every year to provide the same level of services, which means that municipal taxes need to gradually go up to pay for serves or cities need to expand to increase their tax base. As a result, rather than subsidize the poor, most municipalities see it as more in their long term interest to push people into a neighboring (now often suburban) municipality so that they don't have to pay for it.
People from these communities are fully aware of this. This awareness is why we are seeing targeted violence from at-risk minority communities against the tech industry in the Bay Area. This has included attacks on the Google and Apple employee commuter buses and assorted hostility towards tech sector workers. It is also something that I expect we will see much more of across the United States if current trends in inequality and urban displacements persist.
As I noted, their are ways around this. Working in partnership with Community Development Banks (rather than with large retail establishments) as part of site redevelopment so that those at-risk in a community can become business-owners and gain the skill-sets needed to be business owners and the like over the course of a redevelopment project is an example that I am trying to learn more about. Shore Bank in Chicago and some similar organizations have really done some great things that cut against the tendency outlined above. That said, all of this costs money and reduces overall profitability of site redevelopments and as long as we are unwilling to pay taxes and force municipalities to scrap for every dollar and make annual decisions about what city staff they are going to have to lay off next to balance the books, we are not going to see any change.
Regarding gentrification and the response of planning and public policy to it I cannot recommend highly enough Sharon Zukin's fabulous book, Naked City: The Life and Death of Authentic Urban Places. It is clear that planners can be doing a lot more about planning and gentrification and we should be having a much more active and informed public debate on the subject. Attempts, like this piece by NPR to put a positive spin on gentrification for minority populations are active mechanisms for disinformation. They exist to make gentrifiers (many of whom likely make-up much of NPR's listenership) feel better about themselves. The article is actively ignorant of the long, rich and international literature linking gentrification with displacement. It also avoids more complicated questions on the nature of gentrification and the (rather complicated) instances when it may in-fact prove beneficial. The argument that we should be pursuing is not how to avoid making dilapidated urban areas better places to live (I think development is a necessary and good thing), but how to insure that those changes and improvements benefit everyone, particularly those that are most at-risk of displacement.