Economic growth via young singles? Not.

Cities such as Portland have put their stock in creating a vibrant environment that is attractive to young -- often-single, usually childless -- professionals and artists. Their belief is that these people will spark sustained economic growth and vibrancy in downtowns that have otherwise declined.

Not so fast, says Joel Kotkin, a Presidential Fellow at Chapman University in Orange, Calif. In this morning's Wall Street Journal, Kotkin says this effort is "less successful than advertised," and that urban centers traditionally favored by these young singles have experienced below-average job and population growth because of the flight of families to the suburbs:

Cincinnati, Baltimore, Cleveland, Newark, Detroit and Memphis have danced to the tune of the hip and the cool, yet largely remain wallflowers in terms of economic and demographic growth. Instead...the strongest job growth has consistently taken place in those regions--such as Houston, Dallas, Charlotte and Raleigh-Durham--with the largest net in-migration of young, educated families ranging from their mid-20s to mid-40s.

Portland officials might argue that its city isn't in that list, and that its numbers don't play along with Kotkin's argument, but Kotkin responds (emphasis mine):

Advocates of the brew-latté-and-they-will-come approach often point to greater Portland, Ore., which has experienced consistent net gains of educated workers, including families. Yet most of that migration--as well as at least three quarters of the region's population and job growth--has been not to the increasingly childless city, but to the suburban periphery. This pattern holds true in virtually every major urban region.

Kotkin quotes Paul Levy, the president of the Center City district association in Philadelphia, who notes that just 14 percent of Center City residents have children, and half of Center City's residents move out when they hit their mid-30s. Levy continues:

If you want to sustain the revival you have to deal with the fact that people with six year olds keep moving to the suburbs. Empty nesters and singles are not enough....Our agenda has to change. We have to look at the parks, the playgrounds and the schools.

Alas, Portland is too busy building trams and condos amid the concrete jungle -- and too busy closing formerly vibrant school communities -- to worry about providing a place for people with a 6-year-old.