Ezra Klein at WonkBlog discusses the economic engines that are cities:
The three make similar arguments: First, cities make us smarter, richer and more productive. Avent sums up some of the (voluminous) evidence: “Economist Masayuki Morikawa finds that productivity rises between 10 and 20 percent when density doubles. Morris Davis, Jonas Fisher and Toni Whited estimate that a doubling of density may increase productivity by between 17 and 28 percent. Their work suggests that more than 30 percent of real wage growth over the past 35 years is attributable to changes in density.”
Cities, Glaeser says, are “our greatest invention.” People offer ideas and teach skills to, buy services from and engage in healthy competition with one another. Cities enable closer contact among the population. The results can be remarkable.