Economic Evaluation of a National School Feeding Programme Expansion on Child Nutrition and Educational Outcomes in Nigeria

School feeding programmes represent one of the most widely implemented but unevenly evaluated social protection investments in Nigeria, with limited comprehensive economic evaluation linking nutritional and educational return on investment at national scale. This study conducts an economic evaluation of a proposed national expansion of the Home-Grown School Feeding Programme on child nutrition and educational outcomes in Nigeria, combining empirical data collection with decision analytical modelling. Phase 1 conducted a cluster randomised trial in 60 primary schools across three states representing northern, south-eastern, and south-western contexts, comparing programme beneficiaries against matched controls on a battery of outcomes including dietary diversity, haemoglobin, weight-for-age z-score, school attendance, and standardised cognitive assessment scores over two academic years. Phase 2 developed a decision analytic cost-effectiveness model projecting the long-term nutritional and educational effects of programme scale-up using trial data alongside national education and nutrition surveillance data. Cost data were collected through micro-costing of programme delivery, capturing procurement, logistics, preparation, and monitoring components. Incremental cost-effectiveness ratios were calculated relative to current provision levels, and uncertainty analyses including probabilistic sensitivity analysis were conducted. Equity analysis examined differential benefit-cost ratios across income quintiles and gender strata. The study will produce original empirical and modelling evidence on the cost-effectiveness of programme expansion, contributing to evidence-based national social protection investment decisions in Nigeria. Keywords: school feeding programme, economic evaluation, cost-effectiveness, child nutrition, educational outcomes.