No unmixed blessings

Urban economists and urban planners have a renewed interest in the ideas of Jane Jacobs. Richard Florida's work on "creative cities" may have received the most attention, but city success linked to cities' ability to spawn new ideas is now the "hot" area in these fields.  Ed Glaeser's Triumph of the City provides an excellent summary of this thinking.

How, specifically, does it all happen?  Paul Kedrosky cites "ingenuity-sparking collisions;" Glaeser likes "Chains of collaborative brilliance;" my favorite is Matt Ridley's "I believe that at some point in history ideas began to meet and mate and have sex with each other." Sex in the city about does it.
 
But there are no unmixed blessings.  Today's WSJ includes "How Big Cities Can Lead to Small Thoughts."  The writer cites results of some disquieting research and reports that ... "there's nothing magic about concrete and good cappuccino that keeps us from following the herd. ... Sometimes it's a trendy phone, sometimes it's a monolithic political or ideological culture. But whatever it is 'small town' thinking can crop up as easily in megalopolis as in Palookaville."