Robert Neuwirth studies "squatter cities" -- informal urbanized areas home to as many as a billion people worldwide -- in a particularly notable way: he lives in them. We've covered Neuwirth's work before, and greatly appreciate the insights he brings to the question of urbanization and megacities. He has an editorial in the current Fortune magazine, and it provides an excellent summary of his argument:
Peruvian economist Hernando de Soto has proposed that governments should legalize this development by offering squatters the chance to buy title to the land they’re on. [...] But while the idea may sound good (and would doubtless provide long-term employment for the lawyers and surveyors needed to untangle the land-use patterns in these primitive communities), it may not benefit squatters. [...] From the two years I spent living in four of the world’s squatter communities (in Brazil, India, Kenya, and Turkey), I’ve found that squatters need two far simpler conditions to enable their communities to grow. The first is what the U.N. calls "security of tenure"—confidence that they will not be arbitrarily evicted. The second is access to politics—some way to participate in the larger city.
I gotta admit Jamais I like the idea of megacities, more people in a smaller space makes more room for farming land instead of tossing it out the window with suburban sprawl