Birth order effects in developed countries are consistently negative. That is, the later a child is born within a family, the worse their adult economic outcomes relative to their earlier-born siblings are. Studies in specific emerging countries are scarcer and yield conflicting birth order effect signs. Thus, this is the first study analysing birth order effects in a comprehensive group of developing countries, using standardised data and information in 35 countries.
This analysis delivers a consistent picture of birth order effects in an important part of the world, where families tend to be large, and resources are scarce. We analyse nearly 1.8 million observations from the Demographic and Health Surveys (DHS) to measure birth order effects on education in 35 developing countries, between the mid-1980s and 2020. We measure the impact of birth order on standardised years of schooling and school attendance. We find negative birth order effects on educational attainment in 32 out of 35 countries, with little variation by gender, wealth, location, or time in most countries. However, in countries with differences, the negative effects are stronger for children from poorer and rural households.
Birth order effects are a significant source of within-family inequality. Adequately identifying and measuring these effects helps families and policymakers address the differences among siblings. Additionally, birth order should be considered when optimally distributing children into classrooms to enhance peer effects.