The “Baby Boom” (b. 1945-1963) formed the first memorable demographic mouse to pass through the institutional-cultural snake of American society. Then “Gen X” (b. 1977-1987) marked a low-birth saddle between the high-birth “Baby Boom” and “Millennial” generations. . The “Millennial” generation (b. 1980-2005) has stretched the snake even farther than their predecessors. Neither big generation has fully run its course so far. Yet both have had profound impacts.
One feature of the “Baby Boom” appeared in the flood tide toward the suburbs. In a sense, the children of the “Boomers” motivated this migration. The “Boomers” wanted bigger, newer houses with yards to play in and good schools. The life-blood drained out of older American cities as a result.
The “Millennials” reversed this course to some extent by moving back to urban cores in search of a more cosmopolitan life style. They wanted walkable neighborhoods, other young people who shared their own culture, and—for people on the far side of many rights movements–diverse communities.
Moreover, a sharp fall in the violent crime rate made cities seem much safer than when their parents fled in previous decades. Violent crimes—and not just homicide—has been falling since 1991. Studies have begun to reveal that people with higher incomes and more education are alert to changing crime rates. They have shown a greater willingness than other groups to “gentrify” re-claimed areas.
Apartment houses, starter houses, and many services thrived as a result. City governments that benefitted from this population movement crowed over their present revival and contemplated their future prosperity.
Now, however, there are signs that this process may be cresting. Two factors may be at work. First the number of “Millennials” moving into cities has fallen short of rose-tinted projections. Second, the in-flow of younger “Millennials” is being off-set by the out-flow of older “Millennials”—those who are married with children and in their Thirties. Many “Millennials” entered the job market during the “Great Recession.” They’ve faced slow income growth and tight competition for affordable housing. Many of them may have delayed starting families. As they do, however, they may well hear the siren-song of more affordable housing and better schools in the suburbs. Piling on to these forces, at least in some cities like San Francisco, are sharp rises in rents as the very well-off crowd out the only moderately well-off and everyone lower on the income ladder.
It remains to be seen whether the urban renaissance of the early 21st Century will be sustained or will begin to retreat. Sustaining the renaissance probably will require a complicated mix of school funding coupled with school reform, effective policing that keeps crime rates down without alienating people predisposed to see the police as a problem, and a thoughtful approach to keeping housing prices within reach of ordinary people.
 Conor Dougherty, “Cities May Be Starting to Run Out Of Millennials,” NYT, 24 January 2017.
 It seems foolish, if indelicate, to ignore the reality of “white flight” as an important factor. See: https://waroftheworldblog.com/2015/05/21/white-flight-from-baltimore/
 Emily Badger, “To Predict Gentrification, Look for Falling Crime,” NYT, 6 January 2017.
 See: What Government Can Accomplish 1. https://waroftheworldblog.com/2016/12/29/what-government-can-accomplish-1/