Explaining Birth Order Effects on Child Nutrition: Evidence from Kyrgyzstan

This paper examines the effects of birth order on child nutrition in Kyrgyzstan, a lower-middle-income country in Central Asia characterized by a Soviet legacy of universal healthcare, relatively high fertility, widespread multigenerational co-residence, and growing economic vulnerability. Using nationally representative data from three waves of the Kyrgyzstan Multiple Indicator Cluster Survey and a mother fixed-effects design, we find that later-born children have worse nutri-tional outcomes than firstborns, with differences most pronounced and robust for height-for-age (HAZ). Differences in weight-for-age (WAZ) are smaller and less precisely estimated, while weight-for-height (WHZ) shows no systematic varia-tion. Subgroup analyses suggest that birth order disparities vary descriptively across household environments, while formal tests generally do not indicate sta-tistically significant differences across most dimensions. Although grandmother co-residence and higher household head’s education are associated with smaller birth order penalties, they do not fully eliminate birth order disparities.