Chris Wellisz profiles Raj Chetty, who is reshaping the study of social mobility with big data
PHOTOS: NOAH BERGER PHOTOGRAPHY
Archimedes, the ancient Greek mathematician, had his eureka moment after stepping into his bathtub. Raj Chetty’s came while he was taking a shower.
“I imagined this map, and I was thinking it would be really interesting to draw this map of what opportunities for upward mobility look like based on where you grow up,” recalls Chetty, a professor of economics who recently moved from Stanford University to Harvard.
The colorful map that eventually emerged was based on income records of 40 million children and their parents. In shades of red and yellow, it shows huge geographic disparities in social mobility across the country. If you grew up in Charlotte, North Carolina, to parents in the bottom fifth of the income distribution, your chances of reaching the top fifth are just 4.4 percent. In San Jose, California, the odds are almost three times greater.
The map illustrated a 2014 paper titled “Where Is the Land of Opportunity? The Geography of Intergenerational Mobility in the United States.” It was the starting point for a series of studies that have shaped the public conversation about inequal-ity, opportunity, and race. In one, Chetty and his coauthors showed that moving to a lower-poverty neighborhood in childhood significantly improves earnings and college attendance rates in adulthood. In another, they explained why income disparities between blacks and whites persist for generations. And in a widely cited study that casts doubt on the American dream, they found that rates of upward mobility have declined dramatically since 1940.