Measuring Pandemic School-Closure Learning Loss with International Assessment Trend Deviations
Estimating how much student achievement fell during COVID-19 school closures by comparing post-pandemic international assessment results (TIMSS) against each country's own long-term linear trend. A fixed-effects regression with a post-pandemic indicator isolates the deviation from trend, and an interaction with weeks of closure quantifies how loss scales with closure duration, reported in standard-deviation effect sizes across grades, subjects, and student subgroups.
THE LEARNING CRISIS: THREE YEARS AFTER COVID-19
Using TIMSS 2023 mathematics and science achievement data from 71+ education systems and more than 2.8 million grade-4 and grade-8 students, this study estimates how much learning was lost during COV…