Early-childhood education programs that start at birth and care for children until age 5 have a greater economic benefit to society than preschool programs that start later, according to a new study. (iStock )

Nobel Prize winner James Heckman’s research has played an important role in establishing that high-quality public preschool for 3- and 4-year-olds can more than pay for itself over the long term, as low-income children who attend are more likely to live productive lives. It’s an economic argument that has persuaded lawmakers from both parties to support early education initiatives.

Now Heckman has released new research showing that the return on investment is even higher for high-quality programs that care for low-income children from infancy to age 5. Children in such zero-to-five programs are more likely to graduate from high school, less likely to be incarcerated than their counterparts who stayed home or enrolled in low-quality programs, had higher IQs and were healthier during the course of their lives, according to the study released Monday.

All of that taken together leads to a significant savings to society, the study found.

The rate of return on the public investment in zero-to-five programs is 13 percent per year, Heckman and his colleagues estimate, up from an estimate of 7 percent to 10 percent per year for preschool programs that start at age 3.

The more comprehensive zero-to-five programs cost about $18,500 per year for each child enrolled — more than the average public school district spends per pupil in grades K through 12. But for every dollar invested, the program generated a societal benefit of $6.30, according to Heckman.

[James Heckman: In early-childhood education, quality really matters]

He said the findings suggest that policymakers could make a bigger difference in the lives of poor children with early-childhood education programs that begin far earlier in their lives, when children are just eight weeks old.

“As an economist, I always find it very odd that people only focus on the costs of a program rather than the benefits,” Heckman said. “This is very strong evidence for supporting this kind of program going forward.”

Some analysts have challenged the notion that modern public policy should be built around studies of the effects of small, costly programs that cared for children four decades ago, pointing to studies of Head Start and other early education initiatives that have found no lasting impact.

And not everyone is on board with extending taxpayer-provided education to children younger than kindergarten. Speaking earlier this month in the District, Bill Bennett, former U.S. education secretary under Ronald Reagan, said he’s inclined to focus on fixing K-12 education first.

President-elect Donald Trump has proposed tax credits to help working parents pay for day care, but his program is focused on easing families’ financial burden rather than on providing high-quality education for babies and toddlers. He has said little about early childhood initiatives, other than to express skepticism about the cost to taxpayers of the universal preschool programs his Democratic opponent Hillary Clinton favored.

[We have no idea if universal preschool actually helps kids]

Heckman’s new research is based on results from two North Carolina programs that began in the 1970s and then tracked their graduates’ lives through age 35. The two programs — the Carolina Abecedarian Project and the Carolina Approach to Responsive Education — were very similar, enrolling low-income African American infants when they were eight weeks old and caring for them five days a week, 50 weeks a year, until age 5.

Children enrolled in the programs got regular medical checkups, giving their families a better chance of addressing problems early. And because the children were cared for full-time, their mothers — most of whom were single parents — were more likely to get further education and advance at work, boosting their income.

“It has two generations’ impact,” Heckman said.

Graduates of the zero-to-five programs also had higher IQs than their counterparts who did not enroll, Heckman said. Preschool programs for 3- and 4-year-olds have not been shown to have any such effect on IQ.

The two programs initially enrolled about 200 children, a number that diminished as some moved or dropped out for other reasons. Their lives and outcomes were compared to the lives and outcomes of a control group of children, including some who stayed home with their mothers and others who attended low-quality day care.

[How education children early and well creates a ripple effect for us all]

How to define and measure “quality” has been a matter of debate among early childhood educators. Heckman said the defining characteristic of a high-quality program, more than a certain staffing ratio or training regimen, is empathetic adults who engage meaningfully with their young charges, giving them personalized attention as they grow and develop.

Boys who received low-quality care had significantly worse life outcomes, including in health, than boys who stayed home with their mothers, according to the study. Girls did not suffer in the same way from spending time in low-quality arrangements.

Heckman said that might be due to the fact that young boys are, in general, slower than girls to develop skills such as self-control, making them more vulnerable to chaotic environments.

“Quality is probably more of an issue for boys than for girls,” Heckman said. “There’s no question about it that certain kinds of warehouse activity for children — not locking them up in a closet or putting them into Romanian orphanages, but putting them into large groups of children, not even interacting — can lead to harmful consequences,” he said.

He said that boys and girls could benefit from early-childhood policies tailored to their differences, but acknowledged that might be a hard sell: “People don’t want to talk about these gender differences,” he said.

The new research has not yet been submitted to a journal for peer review. It received funding from the Buffett Early Childhood Fund; the Pritzker Children’s Initiative; the Robert Wood Johnson Foundation; the Leonard D. Schaeffer Center for Health Policy and Economics; the National Institutes of Health; the Hymen Milgrom Supporting Organization; the Institute for New Economic Thinking; and the American Bar Foundation.