How many retail, food, and service establishments are there on the streets of New York City? How about Evanston, Illinois? Or Sacramento, California? It turns out the amount of urban street commerce is strikingly related to population size. The biggest metro areas in the U.S. have one retail, food, or service establishment for roughly every 120 people, while the smallest metro areas have roughly one for every 100 people. Store clusters also tend to occur in predictable spatial patterns — with typically a few large clusters of stores, notably more…
