Policy levers for household efficiency: an evolutionary game analysis of multigenerational living and healthcare access

Abstract This study models evolutionary game dynamics among three-generation families and family physicians (FPs) to optimize resource sharing in high-cost, increasingly individualistic societies. While FPs deliver vital preventative care and multigenerational households offer economic and social resilience, rising individualism undermines these structures by prioritizing autonomy over collective bonds, eroding intergenerational support, increasing isolation, and weakening shared legacy. In such contexts, multigenerational living becomes an active, difficult choice rather than a cultural norm in many nations. To counter this, we introduce a novel five-player evolutionary game involving government (G), grandparents (R), parents (P), children (C), and FPs (D), analyzing how policy can stabilize cooperation. Using stability analysis of evolutionarily stable strategies (ESS) and MATLAB simulations based on Hanoi, Vietnam data, we identify key drivers: government subsidies, cost-sharing mechanisms, healthcare collaboration, and mutual benefits. Results show that without government intervention, individualism destabilizes cooperation; with targeted policy support, however, a self-sustaining equilibrium emerges where resource efficiency, lower costs, and improved wellbeing arise organically from structural incentives, not continuous coordination. Government thus plays a pivotal, active role: not merely enabling, but anchoring multigenerational resilience against cultural fragmentation. When incentives align family cost-sharing with FP collaboration, all actors benefit, enhancing health outcomes, financial stability, and caregiving capacity. This framework offers policymakers a pathway to reinforce intergenerational ties while strengthening community-based healthcare. Strategic government action can transform resource-sharing from a fragile, voluntary act into a robust, systemically supported norm, countering individualism’s erosion of family and health systems, and fostering sustainable, cooperative solutions for aging populations, childcare, and rising healthcare costs.