It turned out that Bonnie had been abused as a child and had, as a babysitter, abused others as well. During one of Stacy’s visits, she broke down and confessed her fear of abusing her own child — “especially if it’s a crier.” Stacy suggested some coping mechanisms and wrote down the name of an older woman living nearby whom Bonnie could call for help. Stacy taped the paper to the wall, ready for a crisis. Bonnie did call the older woman, who helped out, and against all odds Bonnie ended up taking quite good care of her baby — which may be why that child ended up graduating from high school many years later. These nurse visits continue until the child turns 2, with the nurse encouraging the mom to speak to the child constantly, to read to the child, to show affection. Later there are discussions of birth control.

The visits have been studied extensively through randomized controlled trials — the gold standard of evidence — and are stunningly effective. Children randomly assigned to nurse visits suffer 79 percent fewer cases of state-verified abuse or neglect than similar children randomly assigned to other programs. Even though the program ends at age 2, the children at age 15 have fewer than half as many arrests on average. At the 15-year follow-up, the mothers themselves have one-third fewer subsequent births and have spent 30 fewer months on welfare than the controls. A RAND Corporation study found that each dollar invested in nurse visits to low-income unmarried mothers produced $5.70 in benefits.

So here we have an anti-poverty program that is cheap, is backed by rigorous evidence and pays for itself several times over in reduced costs later on. Yet it has funds to serve only 2 percent to 3 percent of needy families. That’s infuriating.

There are a couple of lessons we can learn from David Olds and from other programs with a solid record of proven effectiveness. First, it is critical to intervene early, in the crucial window when the brain is developing and the foundations for adult life are being laid. That means helping women avert pregnancies they don’t want and, if they become pregnant, helping them deflect dangers such as drug use, alcohol and tobacco.

James Heckman, a Nobel Prize-winning economist at the University of Chicago, says that our society would be better off taking sums we invest in high school and university and redeploying them to help struggling kids in the first five years of life. We certainly would prefer not to cut education budgets of any kind, but if pressed, we would have to agree that $1 billion spent on home visitation for at-risk young mothers would achieve much more in breaking the poverty cycle than the same sum spent on indirect subsidies collected by for-profit universities.

Second, children’s programs are most successful when they leverage the most important — and difficult — job in the world: parenting. Give parents the tools to nurture their child in infancy and the result will be a more self-confident and resilient person for decades to come. It’s far less expensive to coach parents to support children than to maintain prisons years later.

What does that mean for all of us? We wish more donors would endow not just professorships but also the jobs of nurses who visit at-risk parents; we wish tycoons would seek naming opportunities not only at concert halls and museum wings but also in nursery schools. We need advocates to push federal, state and local governments to invest in the first couple of years of life, to support parents during pregnancy and a child’s earliest years.