A new article suggests that many sociological indicators for urban life conform to a relatively simple mathematical model, and that the model predicts that "innovation cycles" will have to increase consistently in order to avoid urban "stagnation" or social "collapse." Somewhat alarming.

Are cities the main "source" of disease? What sort of disease? When it comes to the "source" of infectious disease I would disagree. When it comes to the spread that is another matter.

Hm, good point. I assumed it meant in terms of transmission -- in the sense that cities foster transmission of infectious disease to such an extent that increasing urbanization will lead to increased incidence of infection. But I didn't read the whole thing yet.