Many fathers and mothers are out of work for some period while their children are growing up, yet the effects on kids of fathers not working has received relatively little attention. This is a significant and growing problem, as about 13 million 25- to 64-year-old men are not working, and several million more are in part-time jobs not by choice, according to U.S. Bureau of Labor Statistics economist Steve Hipple. This number excludes about 1.1 million incarcerated fathers.

“The traditional social-science anxiety was about the effect on children of women working,” said Olivia Golden, executive director of the Center for Law and Social Policy. “But what happens to family income and parental stress and caregiving if fathers don’t work?”

Add to that list, academic achievement, health, and estrangement from fathers, and evidence suggests that the toll on children can be significant.

When the ex-husband of a white Pennsylvania mother did not work for most of his 40s and 50s, their daughter became deeply disappointed in him. Their now-adult son “is still angry and feels his father was very mean to him and did not support us at all,” she said.

Indeed, early research has found that a father losing a job has more adverse effects on children than a mother being out of work (or at work), according to Ariel Kalil, a professor of public policy at the University of Chicago.

In addition to lower family income, household anxiety levels rise. Educational achievement suffers, as the likelihood of a child repeating a grade or dropping out increases; conflicts between teenage boys and fathers escalate; and long-term economic prospects for children deteriorate, according to Gail F. Melson, a professor of child development at Purdue University. With high joblessness among African Americans and the sharp rise in black male incarceration rates since the 1990, such problems are more pronounced among black children.

Although only a few studies have been conducted, the effects on children of parental unemployment — and nonworking fathers in particular — appear to be similar to the widely studied effects of divorce, the increase in births outside of marriage and absent fathers. Compared with kids in two-parent families, children of divorce are more likely to do poorly in school and have behavioral problems, commit suicide, carry guns and deal drugs as teenagers. Girls are more likely to get pregnant, and boys growing up without fathers tend to have more long-lasting problems. Children in single-parent homes are four times as likely to live in poverty as children in two-parent homes: 44 percent versus 12 percent, according to MIT economist David Autor, who suggests that single parenthood may “propagate the inter-generational transmission of inequality.”

Many children of divorce do well, especially when there is committed co-parenting, but all too many men disappear from their children’s lives, and a surprising number of unmarried mothers purposefully keep fathers away from their children.

But fathers can also “disappear” by not working.

Although some nonworking men are active stay-at-home dads, these are the exceptions. Analysis of the American Time Use Survey, conducted by the Bureau of Labor Statistics and the Census Bureau, reveals that nonworking men spend only half an hour per day more caring for children and 25 minutes more per day on housework than men with full-time jobs. What they do with the rest of their time is another story.

Some say that a parent’s job loss can make children more resilient, but when men cannot find a job or stop looking for one or are incarcerated, it can diminish children’s respect for their fathers and provide a less-than-ideal role model about the value of work and responsibility.

Men not working can be a cause of divorce, often exacerbating problems for children. In addition, it can lead to severe rifts between fathers and children, due to family discord and as many nonworking men turn to alcohol, video games, crime and online pornography.

A middle-aged Washington, D.C., woman described her ex-husband as a “super-involved dad,” but when he kept losing or leaving jobs, he had “a lot of time on his hands and spent it in the solitary world of his computer.” “He became a porn addict,” she said. “I worry that, God forbid, our kids will see his computer and see pornography on it.”

As a nation, we need to do more to create jobs and provide better job-training and placement services as well as motivating men to return to the labor force. We also need to place a higher value on fathers, as men — like women — find their identity both as fathers and in their work.

As Kathryn Edin, a sociologist at Johns Hopkins University and co-author of “Doing the Best I Can,” says: “If we truly believe in gender equity, then we must find a way to honor fathers’ attempts to build relationships with their children just as we do mothers’.”

Andrew L. Yarrow, a historian, is the author of four books and a senior fellow with the Progressive Policy Institute. To comment, submit your letter to the editor at https://bit.ly/SFChronicleletters.