Why some low-income neighborhoods are better than others

Chicago’s mayor-elect Lori Lightfoot pledged in her victory speech on April 2 to “make Chicago a place where your zip code doesn’t determine your destiny.” But turning that pledge into reality will require addressing more than poverty, according to a study that followed the lives of thousands of children in the city.

Kids from low-income neighborhoods that are beset by high rates of violence, incarceration and lead exposure earn less money, on average, in adulthood than equally poor children from less hazardous neighborhoods, researchers found. Children from these grittier neighborhoods are also more likely to become pregnant as teenagers or to be jailed in their 20s or 30s as children from less “toxic” communities, the team reports April 1 in the Proceedings of the National Academy of Sciences.

“One thing that’s particularly painful about poverty right now is you’re getting hit from all these different angles,” from higher local crime and violence statistics to more environmental contaminants like lead, says study coauthor Robert Manduca, a sociologist at Harvard University.

Both black and white children who grew up in these toxic communities suffered the long-term effects. But, citywide, black children were more exposed to the hazards than white. Chicago’s neighborhoods remain largely segregated, and predominately black neighborhoods tend to have higher crime and pollution levels, on average, than white neighborhoods, the team says.

In particular, the new results show that if a black boy had grown up with the lower hazards present in a poor white neighborhood, his odds of being jailed by the time he reached adulthood would have dropped from about 12 to 6 percent. And his income in his 30s would have been about $4,200 higher, the team reports. A black girl’s likelihood of teen pregnancy would likewise drop, from 54 to 44 percent.

The work builds on a series of studies over the last five years involving 20 million U.S. children born from 1978 to 1983. Those studies, led by Harvard economist Raj Chetty, showed that a child’s future income is strongly associated with the neighborhood he or she grew up in as well as the child’s race. But Chetty also found large variations in future incomes among children raised in equally poor neighborhoods. 

Harvard sociologist Robert Sampson, a coauthor of the new study, wanted to explore why some poor children fared better than others. He and Manduca focused on children born in the late 1970s and early 1980s, in the same age range as those studied by Chetty. But the pair considered only children whose parents were earning about $27,000 a year in 2015 dollars, to focus on neighborhood conditions and eliminate poverty as a variable. The researchers then tracked those children as they grew older.

From prison data for 1995 to 2000, the sociologists calculated incarceration rates across 754 Chicago census tracts (a census tract has, on average, 4,000 residents and is roughly equivalent to a neighborhood). The team also looked at citizen complaints about violence to the police for the same time frame, as well as lead levels recorded in more than 150,000 blood samples taken from children from 1995 to 1997.

Exposure to high amounts of those three variables helped explain why poor children from one neighborhood grew up to have better upward mobility — or the ability to raise one’s socioeconomic standing — than equally poor children from another neighborhood, the researchers found.  

Most previous work aimed at predicting a child’s upward mobility has focused narrowly on poverty and race, says Christopher Wildeman, a sociologist at Cornell University not involved in the study. By looking at a wider range of neighborhood conditions, the new study “significantly broadens the research on intergenerational social mobility,” he says. 

The researchers are now conducting similar analyses in 54 other U.S. cities.