Offline social capital, online social capital, and fertility intentions: evidence from China

China has experienced both ultra-low fertility and moderate aging in recent years, both of which pose serious challenges to the country's development. Previous studies have shown that social capital is one of the most important factors that influences fertility intentions, but so far empirical research on the relationship between social capital and fertility intentions is very limited. Therefore, this study aims to explore the impact of social capital on fertility intentions and its underlying mechanisms by combining offline and online social capital. Based on data from the Chinese General Social Survey, the fertility intentions of 7,518 respondents aged 18-60 years were analyzed and broken down by sex, region, and age. The marginal effects and mechanisms of offline and online capital on fertility intentions were explored using an ordered probit (oprobit) model, which revealed that individuals' fertility intentions are positively influenced by offline social capital but negatively influenced by online social capital. The role of social capital in shaping individuals' fertility intentions also varies by gender, region, and age. Women, eastern region groups, and those aged 30-60 years are more influenced by offline social capital, and their intentions become stronger as offline social capital accumulates. However, online social capital negatively affects the fertility intentions of women, Midwesterners, and 18-29 year olds. Furthermore, online and offline social capital mainly influence individuals' fertility intentions by affecting their perceptions of pensions, filial piety, and "social justice". Our findings suggest that increasing the value that individuals place on social capital is crucial for improving fertility intentions in China.