Polly Cleveland wrote:  
> I think any plausible theory of growth must start with Adam Smith's and   
> later Jane Jacob's observation that growth happens in cities. Moreover, as   
> Jacobs further observes, growth happens by import substitution under   
> conditions of active competition and trade. Finally, as any development   
> economist can tell us, growth proceeds faster in more egalitarian societies   
> with relatively low levels of corruption.  
>   
> Has anyone built models that incorporate at least some of these facts?  
  
  
But then, Lewis Mumford, who has something in common with Jane Jacobs,   
insists that this urban growth depends upon an almost parasitic   
relationship with the resources of the surrounding area.  Grey Brechin   
wrote a wonderful book, Imperial San Francisco, to demonstrate how this   
worked in a modern city.  
  
  
Michael Perelman