The Harvard economist Raj Chetty, justly famous for his studies of the factors that enable upward mobility in America, is back with a new analysis that has attracted wide attention. Thanks to access to the individual tax records of a million former public housing residents whom his Opportunity Insights team tracked, he determined that a move from “the projects” to a new, mixed-income community led to long-term economic gains for children.

Any federal policy — in this case, the Clinton-era HOPE VI program to demolish crime-ridden public housing such as Chicago’s Robert Taylor Homes, the nation’s largest — that leads to a better life for poor people deserves to be celebrated. Chetty’s findings are being lauded as a demonstration that government housing programs can work, as per the New York Times’s Nicholas Kristof gushing that the study highlights the means for “how to keep the American Dream Alive.”