Unequal Transitions to Adulthood: Widening Disparities in Age at First Union, Sex and Birth in Many Low- and Middle-Income Countries

Comprehensive research on the timing of events during transition to adulthood, such as first union, sex and, birth in low- and middle-income countries (LMICs) focused predominately on measures of central tendency, notably median or mean ages. In this study, we adopt a novel perspective on this topic by examining disparities in the timing of these events in 46 LMICs, spanning four decades. Using Demographic and Health Surveys, we estimate ages at which 25%, 50%, and 75% of women have first union, birth, and sex. We compute interquartile ranges to measure within-country variation and disparities in the timing of sexual initiation and family formation. Variation in the timing of first union, birth, and sex generally increases as the median ages at these events increase. Disparities in the timing of first union and birth grew in West Africa and Latin America, and women who experience these events relatively early increasingly lag behind women who experience them relatively late. Documenting trends in measures of central tendency is insufficient to capture complexity of ongoing changes because they mask growing disparities in the timing of family formation across many LMICs. These results are important for assessing progress towards achievement of SDGs related to eradication of early marriages and childbearing and highlight a need for more holistic approaches to measuring timing of family formation