"A recent World Bank report on global megacities insists that when it comes to spurring economic growth, denser is better: 'To try to spread out economic activity,' the report argues, is to snuff it. Historian Peter Hall seems to be speaking for a whole generation of urbanists when he argues that we are on the cusp of a 'coming golden age' of great cities.
The only problem is, these predictions may not be accurate. Yes, the percentage of people living in cities is clearly growing. In 1975, Tokyo was the largest city in the world, with over 26 million residents, and there were only two other cities worldwide with more than 10 million residents. By 2025, the U.N. projects that there may be 27 cities of that size. The proportion of the world's population living in cities, which has already shot up from 14 percent in 1900 to about 50 percent in 2008, could be 70 percent by 2050. But here's what the boosters don't tell you: It's far less clear whether the extreme centralization and concentration advocated by these new urban utopians is inevitable -- and it's not at all clear that it's desirable."
Kotkin suggests that policies that encourage urban density lead to inequality, and that suburban-style developments offer more choice and more economic flexibility.