A review of the evidence linking child stunting to economic outcomes.

Background: To understand the full impact of stunting in childhood it is important to consider the long-run effects of undernutrition on the outcomes of adults who were affected in early life. Focusing on the costs of stunting provides a means of evaluating the economic case for investing in childhood nutrition. Methods: We review the literature on the association between stunting and undernutrition in childhood and economic outcomes in adulthood. At the national level, we also evaluate the evidence linking stunting to economic growth. Throughout, we consider randomized controlled trials (RCTs), quasi-experimental approaches and observational studies. Results: Long-run evaluations of two randomized nutrition interventions indicate substantial returns to the programmes (a 25% and 46% increase in wages for those affected as children, respectively). Cost-benefit analyses of nutrition interventions using calibrated return estimates report a median return of 17.9:1 per child. Assessing the wage premium associated with adult height, we find that a 1-cm increase in stature is associated with a 4% increase in wages for men and a 6% increase in wages for women in our preferred set of studies which attempt to address unobserved confounding and measurement error. In contrast, the evidence on the association between economic growth and stunting is mixed. Conclusions: Countries with high rates of stunting, such as those in South Asia and sub-Saharan Africa, should scale up policies and programmes aiming to reduce child undernutrition as cost-beneficial investments that expand the economic opportunities of their children, better allowing them and their countries to reach their full potential. However, economic growth as a policy will only be effective at reducing the prevalence of stunting when increases in national income are directed at improving the diets of children, addressing gender inequalities and strengthening the status of women, improving sanitation and reducing poverty and inequities.