For one, says Hanscom, the economy killed their momentum. Millennials are waiting it out at home with their parents:
"There are other factors that have slowed down the great urban migration that predate our recent economic woes: Crime rates are down nationwide, but that has done little to diminish the perception that cities are dark, violent places. Poverty, addiction, and blight still haunt many urban centers. Then there are the kids. The Millenials aren't the first generation of young people to get all stoked about the city. The ones before them continue to pick up and leave as soon as Junior hits school age."
Hanscom has another quite unusual reason why he thinks Americans haven't moved to the city in droves. Read the article to find out.