["The Developing Economies, EarlyView. ", "\nABSTRACT\nTo explore the impact of the pension insurance system on the labor supply behavior, this paper uses microdata from the China Family Panel Studies to analyze the effect of pension insurance participation on overwork. We find that participation in the social pension insurance system can significantly reduce both the likelihood of overwork and excessive working hours. The future economic security provided by pensions substantially enhances workers' sense of occupational safety, and this psychological security net serves as a key mechanism for mitigating overwork. Moreover, pension insurance has a limited impact on work intensity, whereas high work intensity remains a crucial driver of overwork, highlighting the limits of social security policies in improving labor quality. This study provides new evidence on the effects of China's social pension insurance system on labor patterns and offers policy insights for improving workers' quality of life and well‐being in developing countries.\nJEL Classification: I31, J22\n"]