When Rachel Lu describes urban "kiddie deserts," she calls them "a haven for the childless rich, a trap for the poor and a no-man's land for middle-income families."

Cities are among the challenges facing families in America, writes Lu, who teaches philosophy at the University of St. Thomas. In a post called "No Children Here" for the blog of the Institute of Family Studies, she paints two different portraits of Washington, D.C.

In one picture, young adults who have jobs and some personal autonomy enjoy a city rich with history, opportunity and entertainment options. In the other, a third of children live near or below poverty in families that struggle with everything from poor-quality education to simply putting enough food on the table.

It is, Lu notes, not a singular story of one town, but rather the tale of many American cities, where the young and educated flourish and others may not. The impact ripples, because both examples play out against the backdrop of American demography: birth rates dropping, parenthood delayed or foregone, marriage declining in cities more than in other types of communities.

"On a more human level," writes Lu, "it means a rocky road for those who do take the plunge into family life. Raising kids has never been easy, but it is much harder for young people who have few domestic skills and no clear idea of what to expect."

Some of the young adults never move into a family phase, while others may find themselves unprepared for it when they do. Childlessness, meanwhile, is bad for the cities themselves, both economically and culturally. And bad for the rest of the country in terms of such things as having a vital workforce and tax base and more.

Families within cities should not be hidden and thus unfamiliar, Lu says. Even college faculty should let students see faculty children; married student housing should not be off in some corner; and campus lawns should have areas for playgrounds.

Families — and family formation — have undergone some changes. For example, more than half of moms younger than 30 have their first child without marrying — a sequence long entrenched among disadvantaged Americans and now moving through “Middle America” — the 54 percent of Americans who graduated from high school and maybe even got some college, though not degrees, according to a national report called "Knot Yet," released by the National Marriage Project at the University of Virginia, the National Campaign to Prevent Teen and Unplanned Pregnancy and the RELATE Institute.

Those babies, it notes, are being born to single mothers and to couples who are living together but not married. Cohabiting couples are more likely to break up than are those that married.

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