Global patterns in STEM teacher shortages: Evidence from TIMSS 2011–2023

Shortages of mathematics and science teachers are widely cited as a global challenge, yet little is known about how these shortages evolve over time or how they are distributed across schools. Drawing on principal reports from four cycles of the Trends in International Mathematics and Science Study (TIMSS 2011–2023), this study examines longitudinal patterns in mathematics and science teacher shortages at Grades 4 and 8 across more than 40 education systems. Focusing only on countries that took part in all four cycles, we calculated the percentage of schools reporting teacher shortages and compared these rates by school socioeconomic level and urban versus rural location. Results show that teacher shortages consistently affect a majority of schools worldwide, with pooled rates typically exceeding 60% across cycles. At Grade 4, science shortages are systematically higher than mathematics shortages, affecting nearly two-thirds of schools in every cycle, whereas Grade 8 shortages display greater temporal volatility. Crucially, shortages are strongly and persistently stratified by socioeconomic status: schools serving socioeconomically disadvantaged students report shortage rates that are typically 10–20 percentage points higher than those in more advantaged schools, with persistent gaps across all cycles. By contrast, urban–rural differences are smaller and less systematic. These findings suggest that STEM teacher shortages are not merely a supply problem but a durable form of educational inequality.