Abstract
With the growing and aging population round the world, it becomes increasingly important to understand what factors impact the mental health and cognition of the older generations in order to design effective interventions. In this paper, we investigate the effect of a child's gender on parental mental health and cognition in the context of one of the world's largest developing countries and the unique one-child policy, using China Family Panel Studies (CFPS). We exploit the exogeneity of the first child's gender and find that having a son has significant protective effects on parents' mathematics performance and memory functions in one-child families, but such effects are absent in multi-child families. Moreover, we find that the protective effect is more pronounced among one-child families in rural areas than urban areas. Our results suggest the existence of gender inequality in China and reveal the hidden long-term social cost of the one-child policy.