Deworming pills dramatically improve children's schooling in poor countries.

Miguel & Kremer (2004) ran a randomized deworming programme in Kenyan schools and found it sharply cut absenteeism, partly through 'spillover' benefits to untreated children nearby. The study became a foundation of the effective-altruism case for deworming as a cheap way to boost education, channelling large donations.

But the broader medical literature is far less rosy. Cochrane reviews (Taylor-Robinson et al.) of many mass-deworming trials found little or no effect on weight, haemoglobin, cognition, school attendance, or performance. A high-profile re-analysis of the original Kenya data also revised some findings. Both sides remain active, with disputes over methods, spillovers, and worm prevalence. The strong 'deworming transforms schooling' claim is genuinely contested — the flagship result has not clearly generalised.