Ed Glaeser, writing in the Boston Globe, notes their strong connection (via Mark Thoma):
Across countries today, there is a robust correlation between urbanization
and democracy. This correlation reflects many things, such as the tendency of
more urban places to be richer and better educated, but it also surely reflects
the role that cities play in supporting the coordinated action that creates and
defends democracies
July 10th, 2008 at 12:28 pm
George Will makes the case that urbanization, and therefore civilization, depended on beer. I’ll drink to that.
http://www.townhall.com/Columnists/GeorgeWill/2008/07/10/no_beer,_no_civilization