["Oxford Bulletin of Economics and Statistics, EarlyView. ", "\nABSTRACT\nWe examine the relationship between the assignment of homework and student achievement among 8th grade students across 23 countries using the TIMSS 2019 dataset. Exploiting within‐student, between‐subject variation in homework assignment, we find a small but statistically significant positive relationship between homework and achievement. This benefit is driven primarily by the frequency with which homework is assigned rather than its volume. Heterogeneity analyses suggest larger benefits for students with more highly qualified or more experienced teachers, while effects are broadly uniform across the performance distribution except among particularly weak students. We also document substantial cross‐country variability in these estimated effects.\n"]