Having rich childhood friends is linked to a higher salary as an adult

Children who grow up in low-income households but who make friends that come from higher-income homes are more likely to have higher salaries in adulthood than those who have fewer such friends. "There's been a lot of speculation… that the individuals' access to social capital, their social networks and the community they live in might matter a lot for a child's chance to rise out of poverty," says Raj Chetty at Harvard University. To find out how if that holds up, he and his colleagues analysed anonymised Facebook data belonging to 72.2 million people in the US between the ages of 25 and 44, accounting for 84 per cent of the age group's US population. It is relatively nationally representative of that age group, he says. The team used a machine learning algorithm to determine each person's socioeconomic status (SES), combining data such as the median income of people who live in the same region, the person's age, sex and the value of their phone model as a proxy for individual income.