Mincy is a co-founder and co-investigator of Princeton's Fragile Families study. Thus far, its various findings include:

•Compared with married parents, single parents tend to be younger by an average of five years. Three-quarters have a high school diploma or less education, while 3 percent have a college degree.

•Children reared in stable, cohabitant homes display more behavioral problems, including aggression, anxiety and depression, than those in stable, married homes.

•Unmarried fathers are more likely to be jobless and suffer health problems that hinder their employability.

Says Dr. Waldo Johnson, an associate professor in the University of Chicago's School of Social Service Administration and a Fragile Families co-investigator: "We're trying to make the case that the labor market, in many ways, shapes the context for parenting for many men."

Deadbeat, Dead broke

A forthcoming book Mincy has co-authored is about the economic reality and prospects for low-income men, six of 10 of whom are fathers. Of course, some are deadbeats, shirking their financial and other parental obligations. But a good portion of them are dead broke, Mincy adds.

Policymakers and lawmakers recognize that the latter group must be dealt with in a manner that benefits them and their children. As an outgrowth of that, several states are reducing the amount of delinquent child support owed each time a father pays down that debt. Another outgrowth includes projects such as the Center for the Urban Family in Baltimore that trains men in parenting.

As a next frontier, Mincy says researcher-advocates are pushing for single fathers something akin to the federal Earned Income Tax Credit, a $50-billion-a-year subsidy that mainly goes to single moms.