The hierarchical diffusion of AIDS and violent crime among U.S. metropolitan regions: inner-city decay, stochastic resonance and reversal of the mortality transition.

Census data on migration within and between the 25 largest U.S. metropolitan areas-containing more than 113 million people-permit construction of a probability-of-contact matrix corresponding to a particular Markov process dominated by the nation's largest cities, a hierarchical structure. Regression models based on vectors associated with that process find the large-scale diffusion of AIDS in the U.S.A. depends strongly on national patterns of contact with the original AIDS outbreaks in New York City and San Francisco as modulated by the violent crime rate, a local index of social disintegration resulting from the marginalization of minority ethnic urban communities. Violent crime is itself undergoing a recognizably similar hierarchical diffusion from the largest U.S. cities into smaller metropolitan regions. Further analysis suggests that continuation of public policies of "benign neglect" and "planned shrinkage" directed against marginalized urban populations may trigger a strong stochastic resonance which can significantly degrade public health and public order for much of the three-quarters of the U.S. population living in or near cities, in effect reversing the mortality transition of the last century.