From the paper: "Since the pandemic started in March 2020, multiple reports have highlighted large declines in students’ math and reading achievement as well as widening gaps by race and school poverty. If allowed to become permanent, such losses will have major impacts on future earnings and intergenerational mobility. We use student-level data from 2.1 million students in 10,000 schools from 49 states (plus D.C.) to compare students’ achievement growth during the pandemic (Fall 2019 to Fall 2021) to a pre-pandemic period (Fall 2017 to Fall 2019). In addition to documenting the magnitude of the learning loss, we investigate the role of remote and hybrid instruction in widening gaps in achievement by race and school poverty."