From the brief: "This brief focuses on the impacts of Summer  2021 school extension programs on students who were enrolled in grades 9 through 12 in the 2020-21 academic year and remained enrolled in North Carolina public high schools in the 2021-22 academic year. For our analyses, we use administrative data from NCDPI on students in all North Carolina public high schools in the 2020-21 and 2021-22 school years combined with enrollment data from the Summer 2021 school extension programs."