Over the course of the 2020-21 school year, students across the United States experienced educational disruptions as schools and districts alternated between learning modes in an effort to mitigate the transmission of COVID-19. Uncertainty about the role of schools in the spread of COVID-19 as well as the impact of different schooling modes forced school leaders to make difficult decisions about how to appropriately support both their students and staff. School districts utilized a range of schooling modes (sometimes called "learning models") throughout the year: some remained closed and offered virtual learning options, others opened for full-time in-person learning, and some combined these approaches through a "hybrid" schooling mode. Approaches to both hybrid and virtual learning varied, including different numbers of days in school and variations in the degree of synchronous instruction.
In this paper, Emily Oster and her co-authors use data on district schooling modes alongside Spring 2021 test score data from 12 states to analyze the relationship between schooling mode and test scores. They estimate the relationship between the share of the year that in-person learning was offered (as opposed to hybrid or virtual learning) and student standardized test scores, both overall and interacted with district demographics.