Barkley, these questions can only addressed by professional city planners, biologists, agronomists, economists, systems analysts working in tandem in post-capitalist society. I don't bite off more than I can chew. What I have chewed up and digested is the whole problem of environmentally unsustainable production. My solution is to abolish the capitalist means of production so that the profit motive does not impinge on our ability to rationally plan production and population distribution, which are dialectically related. The reason cities come into existence is that the capitalist class required them. If you read Comninel's book on the French revolution, you will discover that the largest city in France in the 1780s was tiny compared to some of England's smaller cities. The reason for this is that England had gone further than any other European country in developing the capitalist means of production.
I suspect that cities of our socialist future will contain far fewer megacities like NYC or Mexico City and that they will be much closer geographically to, and better integrated economically with, their agricultural suppliers. While the World Watch Institute is a bourgeois institution, they do raise some very interesting ideas about softening the contradiction between town and country. In the Sept/Oct. 1998 issue, there is an article "How Mid-Sized Cities Can Avoid Strangulation" by Molly O'Meara which takes the position that "Contrary to popular impressions, the urbanizing of the world means a proliferation not only of giant 'megacities' but also of a larger, faster-growing class of middle-sized cities. In their struggles to overcome the pervasive problems of traffic, polluation, chaotic development, and psychological stress, two of these mid-sized cities serve as encouraging models."
The problem with this article is that in a real sense it is utopian. The utopianism is a function of the inability to understand that capitalism is accelerating the urbanization process for reasons endemic to the system. The most pronounced tendency, by the way, is not people pouring into the inner city but the sort of sub-suburbanization taking place on the outskirts of Los Angeles that Mike Davis is quite rightly sounding the alarm on. When you build houses in the desert, you have to drain water from surrounding states hence causing desrtification in places that are naturally fertile while diverting water to swimming pools, lawn sprinkler, air conditioners, etc. What we are headed toward is cities that will eventually strangulate themselves.
Louis Proyect
(http://www.panix.com/~lnp3/marxism.html)