Happy mothers, healthy minds: Maternal welfare and children's early development in the global south.

In low- and middle-income countries (LMICs), maternal well-being remains critical yet understudied in relation to early childhood development, particularly where poverty and systemic discrimination persist. This study examines the heterogeneous impact of mothers' subjective well-being, as measured by self-reported life satisfaction, on the developmental outcomes of children under the age of five. Leveraging data from the sixth round of the Multiple Indicator Cluster Surveys (MICS6) from 2018 to 2020 on approximately 160,000 mother-child dyads across 31 LMICs, the analysis exploits a novel instrumental variable strategy based on conditional exogenous shocks from the loss of a close family member. Given specific assumptions, most notably treating the timing of a sibling's death as conditionally exogenous with respect to children's developmental outcomes, this research design provides evidence that goes beyond simple associations. Furthermore, by integrating macro-level country data, a simple interaction framework is employed to examine which contextual factors, economic conditions, quality of public governance, and human development serve as the most influential moderators of this relationship. The findings highlight two key insights: (i) maternal life satisfaction, measured through four distinct dimensions, is conditionally linked to reductions in children's social competence deficits and functional difficulties; and (ii) macro-level factors, particularly economic development, governance quality, and human capital, significantly amplify this effect. Ultimately, this study contributes to the literature by offering evidence on how policymakers may enhance sustainable development outcomes for future generations by prioritising macroeconomic reforms.