By contrast, fewer than half of 1 percent of men from the richest 10 percent of families were imprisoned on any given day in their early 30s.
That stark relationship — between childhood family income and adult incarceration — underscores how much the environments children grow up in can shape their life trajectories.
To produce their analysis, Looney and Turner collected Internal Revenue Service tax returns for 2.9 million incarcerated individuals. For a subset of about 500,000 of those inmates, they were able to link incarcerated individuals to their parents’ income tax returns, providing snapshots of where the future inmates were born and how much money their families made at the time of their birth.
They found that income was a strong predictor of future incarceration: boys born into the bottom 10 percent of the income distribution (average family income of about $14,000) were about 20 times as likely to end up incarcerated as boys born into the top 10 percent (about $143,000).
While the incarceration rates for girls were much lower, the data showed a similarly sharp incarceration gradient running along the income spectrum.
They also found that children from single-parent families were about twice as likely to end up incarcerated as the children of married parents, regardless of family income.
Children of poor families are thus heavily overrepresented in the prison population. Among the cohort of prisoners age 28 to 34 the authors examined, the bottom 5 percent of families, by income, produced about 30 percent of the inmates. The bottom 20 percent of households produced nearly half the inmates, while the bottom 50 percent of families accounted for over 82 percent of inmates.
Incorporating family structure into the analysis, the study found that “boys from single-parent families in the bottom 10 percent of the income distribution — a group that makes up only 3.7 percent of the overall population” — accounted for 20 percent of all prisoners in 2012. Conversely, boys with married parents who grew up in the top 50 percent of households accounted for 46 percent of all boys but only 14 percent of men in prison.
The data also allowed Looney and Turner to map out prisoners’ places of birth. That map, below, indicates that prisoners are “disproportionately likely to have grown up in socially isolated and segregated neighborhoods with high rates of child poverty and in predominantly African American or American Indian neighborhoods.”
In a number of Zip codes, future incarceration rates topped 10 percent. For instance, 1 in 7 children (male and female) born in North Nashville, Tenn., between 1980 and 1986 could expect to end up incarcerated on any given day in their early 30s, the highest rate in the nation among high-population Zip codes.
“The neighborhoods with high incarceration rates are predominantly black, or are otherwise nonwhite, have child poverty rates that are two to three times the national average, and have male unemployment rates substantially higher than the rest of the country,” Looney and Turner found.
“Poor African American and Native American boys living in segregated communities of concentrated poverty are highly unlikely to experience anything but unemployment or incarceration or both,” wrote the Brookings Institution’s Camille Busette in an accompanying commentary. “If we add to this the fact that police disproportionally kill African American and Native American men, it is clear that the level of exclusion faced by these men is staggering.”
Other research has shown that one way out of the cycle of poverty, violence and incarceration is to get out — literally. A 2015 study by Raj Chetty and colleagues found that “moving to a lower-poverty neighborhood significantly improves college attendance rates and earnings for children who were young (below age 13) when their families moved.”
But moving is disruptive and expensive, and families whose children stand to gain the most from moving to a new neighborhood are, almost by definition, the ones least able to afford such a move.