According to Florida, "researchers at the Santa Fe Institute have been able to demonstrate that bigger, denser cities literally speed up the metabolism of daily life....Doubling a city's population, the Santa Fe researchers found, more than doubles its creative and economic output, a phenomenon known as 'superlinear scaling.'"
So how should cities stimulate density? By building up, of course.
Not so fast, says Florida. The means to achieve density are more important than the ends, he argues. Take Shanghai for example, where densities can approach 125,000 people per square mile, but whose output of innovation and creativity, "pales in comparison to New York, London, Paris and Milan." The cause for this discrepancy, Florida writes, is that, "what matters most for a city's metabolism-and, ultimately, for its economic growth-isn't density itself but how much people mix with each other."
And this mixing, what Peter Gordon of the University of Southern California and Sanford Ikeda of the State University of New York, Purchase call "Jacobs density", is the key to understanding the sociological component to how density works. This type of density, in contrast to what Gordon and Ikeda term the "crude" density of tall buildings, is what "sparks street-level interaction and maximizes the 'potential informal contact of the average person in a given public space at any given time.' It makes networking and informal encounters more likely and also creates a demand for local products and diversity-not just of populations and ethnic groups but of tastes and preferences."