The team dug into the long-term effects of a huge neighbourhood revitalisation program called Hope VI. Beginning in 1993, Hope VI invested $17 billion to replace 262 high-poverty public housing projects around America. That was Hope VI, which replaced them with mixed-income homes — meaning fewer housing units for the poor, something that was controversial. Presumably the families appreciated better public housing and safer neighbourhoods, but by themselves the improved apartments did not defeat poverty. —Contact Nick Kristof at Facebook.com/Kristof, Twitter.com/NickKristof or by mail at The New York Times, 620 Eighth Ave., New York, NY 10018.