The science on remote schooling is clear. Here’s whom it hurt most.

Academic progress for American children has plunged during the coronavirus pandemic. Now a growing body of research shows who was hurt the most, both confirming worst fears and adding some new ones. Students who learned from home fared worse than those in classrooms, offering substantial evidence for one side of a hot political debate. High-poverty schools did worse than those filled with middle class and affluent kids, as many worried. And in a more surprising finding, older students, who have the least amount of time to make up losses, are recovering much more slowly from setbacks than younger children. A pile of evidence charts setbacks that were more severe the longer students stayed in virtual school. These studies examined the impact of in-person vs. remote education during the 2020-21 school year, when policies varied widely. There were modest academic declines for students who quickly returned to in-person classes in fall 2020. But achievement losses were far higher for those who learned from home, and they were most pronounced for students in high-poverty, mostly remote schools, widening long-standing racial and economic achievement gaps. Students who were in person full-time during 2020-21 lost an average of 7.7 weeks of learning in math. But those who were in virtual class for more than half the year lost more than double that — an average of 19.8 weeks. Reading achievement in school districts that went fully remote fell, on average, two or three times as much as it did for those studying in person during the 2020-21 school year.