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 nutritional 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 variation. Subgroup analyses suggest that birth order disparities vary descriptively across household environments, while formal tests generally do not indicate statistically 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.