It's a chicken and egg problem: it's hard to artificially create centers of population density. China is doing it, with mixed results, because they can just rel

It's a chicken and egg problem: it's hard to artificially create centers of population density. China is doing it, with mixed results, because they can just relocate people. It's not as much building new cities, but expanding cities. One of the reasons for Manhattan's "success" as a city is it's physically constrained, so developers build up, so population density increases. All the development happening in the Seaport area of Boston is a good example. The Fort Point area, just north of the Seaport, was an artist enclave until recently, when people were priced out of the city and buildings started flipping in Fort Point. Now, there are multiple luxury high rises being built on the water, and tech companies are moving into the area. Artists moving to Detroit will happen, but it will take a lonnnnng time to gentrify the city, just like it took decades to bring NYC from what it was in the 1970s to now.