Does Fertility in Women Influence Sustainable Economic Independence? Comparative Analysis Between South Africa and Kenya

This study examines whether fertility-related employment penalties differ across countries at different stages of demographic transition, using Kenya and South Africa as comparative case studies. Using nationally representative Demographic and Health Survey (DHS) data, the analysis employs an instrumental-variable approach that exploits exogenous variation in fertility generated by twin births, with the sex composition of the first two children used as a supplementary robustness instrument. A Principal Component Analysis (PCA)-based Economic Independence Index is also employed as an alternative outcome measure to capture broader dimensions of economic autonomy. The results show that higher fertility significantly reduces women’s paid employment participation and broader measures of economic autonomy. Instrumental-variable estimates exceed ordinary least squares estimates, suggesting that conventional models underestimate the economic costs of childbearing. Fertility-related employment penalties are remarkably similar across Kenya and South Africa despite their different demographic transition trajectories, providing little evidence that lower-fertility contexts experience weaker employment penalties. The adverse effects are strongest among women with higher parity and lower educational attainment, highlighting important life-course heterogeneity. The study contributes comparative causal evidence on fertility-related employment penalties across two Sub-Saharan African countries using a common quasi-experimental identification strategy. The findings have implications for Sustainable Development Goal (SDG) 5 (Gender Equality) and SDG 8 (Decent Work and Economic Growth) by demonstrating that demographic change alone is unlikely to improve women’s labour-market outcomes. Instead, policies that reduce childcare constraints and strengthen women’s labour-force participation may help mitigate fertility-related employment penalties and promote more inclusive and sustainable development.