Nearly half of American children experience poverty before they reach their 18th birthday, and that reduces their chances of having a stable childhood and finishing high school and college, a new study by the nonprofit Urban Institute concludes.

The study — “Child Poverty and Adult Success” — analyzed data of people born between 1968 and 1989 from the “Panel Study of Income Dynamics,” which follows 18,000 individuals and 5,000 families over the course of their childhood. It used over 40 years of data to follow poor children, creating a picture of why some succeed as adults — and others do not. Children as a group are disproportionately poor, according to the 2014 Census: Roughly one in five children live in poverty in the U.S. compared with one in eight adults.

Some American children have a better start in life than others

Source: Urban Institute Credit: Urban Institute

Although it depends on where you live, the federal poverty level translates to annual income of $11,770 a year for individuals and $24,250 for a family of four, according to the Department of Health and Human Services; federal poverty levels are used to determine a person’s or family’s eligibility for certain social programs and benefits. Four of every 10 children (39%) are poor for at least one year before they reach their 18th birthday. Black children fare much worse: More than 75% are poor during childhood. The percentage for white children is also substantial, yet far lower (30%).

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If a parent doesn’t have a high school diploma, the child most likely won’t get one either

Children who fell below the federal poverty line at least once during their childhood (“ever poor”) and whose parents have more than a high school education are 30% more likely to complete high school and five times more likely to complete college than children whose parents did not attend.

Unstable homes are related to lower academic achievement and less consistent employment

Those who were poor at least once during childhood and who moved three or more times for financial reasons are 15% less likely to complete high school, 68% less likely to complete college, and 24% less likely to be consistently employed as a young adult than those who didn’t move.

Growing up with two generations of family can help a child achieve a third-level education

Children who are poor for more than half their childhood — but lived with a parent and grandparent — are over three times more likely to complete college than children who never lived in a multigenerational family. This wasn’t the case for kids who were poor at least once during childhood.

Falling below the poverty level in childhood can haunt adult educational achievement

Children who are poor are less likely to achieve critical milestones, such as graduating from high school and enrolling in and completing college, than children who were never poor. While 93% of “never-poor” children completed high school, the study found, only 78% of “ever-poor” children did.

Getting arrested and teenage pregnancy out of wedlock are more likely if you’ve been poor

Americans who were poor in childhood are also more likely to have a non-marital teenage birth (22% versus 4% for children who were never poor) and some involvement with the criminal justice system by the age of 20 (24% of children who have been poor compared with 16% of “never poor”).

What does it all mean? “This should encourage more public programs to encourage parental education and keep children in schools, even if they cross county lines,” says Caroline Ratcliffe, senior fellow at the Urban Institute. “A lot of things matter for the economic mobility of children, even their neighborhood,” adds Erin Currier, director of The Pew Charitable Trusts’ financial security and mobility project. The Pew Charitable Trusts is a nonprofit organization with a goal to improve public policy. While living in a low-income family doesn’t preclude social mobility, America is more likely to be the land of opportunity for those who are white and had a childhood free of any financial hardship.

While other recent studies have shown that your parents’ income determines your future income, public opinion appears to contradict these studies on who can achieve the American dream—loosely interpreted to mean those who do significantly better than the previous generation—and why, a 2011 public opinion poll carried out by The Pew Charitable Trusts found. More than 80% of Americans identified factors such as hard work, personal ambition, and access to education as key drivers of upward mobility, while less than half viewed growing up in a good neighborhood as an important factor, it added.

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