Abstract
School absenteeism and disengagement remain persistent challenges in secondary education in Uruguay. Over half of young people aged 21–23 have not completed secondary school, and students in lower secondary education accumulate, on average, more than 30 absences per year. This study evaluates the impact of a behavioral intervention designed to improve attendance in 7th grade of Basic Integrated Education, a critical transition point in students’ educational trajectories. The intervention leverages salience by sending brief, personalized WhatsApp messages to families with timely information on students’ accumulated absences, key academic dates, and insufficient grades. We assess the program through a clustered randomized controlled trial involving 255 public secondary schools and more than 30,000 students nationwide. We find that assignment to the treatment reduces absenteeism by 7%, equivalent to 2.2 fewer days absent per academic year. Instrumental variable estimates indicate a larger effect of 3.4 fewer days among students attending schools that effectively implemented the program. We complement the impact evaluation with process evidence to explore the mechanisms underlying these effects. Results suggest that the intervention operates primarily by reducing informational frictions between schools and families and increasing the salience of attendance information at critical moments, rather than by shifting underlying beliefs about absenteeism. These findings highlight the potential of low-cost, scalable behavioral interventions to strengthen family engagement and reduce absenteeism in secondary education, particularly in contexts with high risks of educational disengagement.