The Economics of Agglomeration

Why do cities exist? In this Internet age, why do they continue to exist? Probably, so we can step in each other's dog poop and smell other people's cigar smoke? Perhaps, there are gains to trade that are facilitated by being in tight proximity that overcome the annoying noise, smoke and foulness of cities?

The NBER has invested some $ to try to test some new hypotheses concerning the causes and consequences of agglomeration. Here is the program:

http://www.nber.org/~confer/2007/EAs07/EAs07prg.html

If you will be in Cambridge on Friday, you can present my paper for me. I will be to your west.