Cities and marketplaces are central to economic development, but we know little about why such agglomerations initially form. I argue that evolutionary forces select for agglomerations when individuals' desire to spatially coordinate exchange in complex environments. To test this idea, I perform...

We study the location of more than 1,000 research and development (R&D) labs located in the Northeast corridor of the U.S. Using a variety of spatial econometric techniques, we find that these labs are substantially more concentrated in space than the underlying distribution of manufacturing...

The authors study the location and productivity of more than 1,000 research and development (R&D) labs located in the Northeast corridor of the U.S. Using a variety of spatial econometric techniques, they find that these labs are substantially more concentrated in space than the underlying...