Code for: "Does the 'Boost for Mathematics' Boost Mathematics? A Large-Scale Evaluation of the 'Lesson Study' Methodology on Student Performance"

Students in East Asian countries dominate international assessments. One possible explanation for their success is the use of “Lesson study” to enhance teaching practices; a collaborative pro-cess where teachers plan, observe, and analyze a lesson together. We evaluate a national teacher development program in Sweden – “Boost for Mathematics” – containing core elements of Les-son study. Exploiting the gradual roll-out of the program across compulsory schools, we find that it improves teaching practices and boosts students’ mathematics performance. The positive effect on student performance persists also long after the intervention has ended. The program also passes a cost-benefit test.