Kathryn Edin, a sociologist at Johns Hopkins University, traveled the country for six years, asking single moms in poor neighborhoods: How do you make ends meet? She wasn't interested in the children's dads, who appeared to offer little help. "They seemed like scummy characters," Edin said. "Disreputable types."

But then she met Sam, a poor father in Philadelphia -- and hundreds of men like him, who don't pay formal child support. Their stories, she said, broke the stereotypical narrative of "deadbeat dad."

After his girlfriend announced she was pregnant, Sam, a cocaine dealer, switched to installing carpets, he told the academic. He wanted the child to have a crib, a pantry full of baby food and a tiny pair of Air Jordans. He would hand-deliver them, a joy impossible from prison.

But days before his baby girl was due, addiction tugged. Sam landed behind bars for 18 months, hoping for a fresh start and, eventually, partial custody. When he got out, he scraped together money to buy diapers, his first fatherly offering.

Less than a third of fathers who make poverty wages and don't live with their children pay formal child support, a 2007 study found. These dads, however, may provide much more for their kids than research has previously revealed, Edin learned. Many provide in a different way, one that government agencies don't often track.

“They don’t often don’t live with the mothers, and some don’t know when they’ll be able to see their child next,” said Edin, whose findings were published this month in the Journal of Marriage and Family. “So, they want to give the kids something to hold, a symbol of their love. Kids don’t know if the father pays the electricity bill, but they’ll know if the father brings food.”

In the United States, about one in four kids are due some child support. Only 62 percent, however, receive the full amount owed.

Edin’s team of researchers spent nearly a decade interviewing 367 fathers across racial backgrounds in neighborhoods more privileged Americans might describe as rough. They recorded every purchase the dads made for their kids, collecting receipts and price-checking at grocery stores.

Only twenty-three percent of the fathers paid support through the court system, offering a monthly average of $38.

But nearly half  contributed “in-kind” support to a child, or items instead of cash, spending an average of $60 each month, per child, on different goods: formula, Pampers, strollers, Air Jordans. Out of these fathers, about 16 percent contributed no formal child support payments, making them "dads who would traditionally be considered 'deadbeat,'" the authors noted. They gave $63 per child a month through in-kind support.

“Many of the men we consider to be ‘deadbeat dads’ aren’t actually ‘deadbeats’ at all,” Edin said. “They’re doing the best they can, and what they offer undocumented often turns out be a large chunk of their income.”

The total amount of fatherly support did not vary by race, but the nature of that support did. Compared to dads of other races, black fathers offered the highest proportion of support through items: 44 percent, compared to 35 percent.

The level of support increased with access to kids for every racial group, researchers found: Dads who spent at least ten hours each month with their children gave them about $84 worth of goods, nearly twice as much as dads who rarely saw their kids.

While some fathers simply didn’t make the effort to see their kids, Edin said, many said the mothers of their children sometimes prevented visits. "A number of fathers reported that, to get around the gatekeeping of the mother, they met their children surreptitiously after school and treated them to a fast food meal before their children made their way home," the study authors found.

The policy implication: It’s time for child support agencies to track in-kind contributions, Edin concluded.

That's not to suggest diaper donations should replace rent assistance, especially when mothers, more often the sole custodians, may have a better understanding of what a child actually needs, she said. Updating the law to count in-kind contributions may encourage fathers to provide even more for their children. It may also prevent one parent from claiming back-pay if the other parent had been buying, say, all the food and diapers for six years.

And it may help demolish the misconception that poor fathers are deadbeat dads.

Sam, whose baby girl is now 12, told researchers he takes her to McDonald’s for a Happy Meal every other weekend.

He has stopped dealing drugs and works full-time as a handyman, Edin said, earning enough to rent an apartment. As he builds a more stable life, his father has custody of his daughter. (Her mother was also fighting a drug addiction, he said, and lost custody.)

Though Sam trusts his dad, he’d rather support Nicole with gifts.

He buys her Water Ice, their favorite Philly treat, and dresses for school, which suit her better than Air Jordans. He told the sociologist: It’s how I feel like a provider, a real father.