I read an article in today’s BBC news about a magazine by and for slum dwellers in India. It’s different from the Street Spirit/Spare Change/other publications by the homeless that you see in the states, because the target audience is not the guilt-ridden middle class. It reminds me of a paper I read about “Serving The World’s Poor, Profitably, which made the claim that slums have functional economies on their own and that companies, rather than treating slums as a problem to be solved by the goverment, can instead provide services and goods to slum dwellers, improving their standard of living, while at the same time making (some) profit. When I first read it, it seemed exploitative, but now I’m wondering if market forces really can make substantial differences in the quality of life for the urban poor.
Part of what helped change my mind was hearing a talk about Project Impact, which tries to develop cheaper manufacturing methods for medical technologies and spin those off to companies in India. These things make me wish I did more socially redeeming engineering work.
An Ergodic Walk 
A recent book on the issue is Hernando de Soto’s The Mystery of Capital and it says very similar things. Just formalizing the de facto property rights recognized in the urban slums of the world would transform them overnight because then each slum dweller would have a better incentive to invest in his little corner lean-to and not fear that his efforts would be for nothing come the next police raid. Long book, and I’ve not yet read it, but the precises I’ve read make powerful arguments about this.