Descriptive statistical analysis of variables.

Individuals in different life stages have different intentions and reasons for migration, which leads to differences in the spatial patterns of migration across age groups. This paper aims to reveal the different patterns of inter-provincial migration across age groups and the underlying driving factors to foster a deeper understanding of migration phenomena in China and support an appropriate policy response. Using data from the 2017 China Migrants Dynamic Survey and an extended gravity model with lasso-penalized Poisson regression, we reveal significant heterogeneity in migration patterns among different age groups. In terms of spatial patterns, while people of all age groups tend to migrate from less developed regions to more developed regions, the migration flows of the working-age population are primarily short-distance relocations from populous central provinces to economically developed areas, whereas elderly individuals migrate predominantly from northern regions to Beijing and from southern regions to Shanghai. In terms of influencing factors, while economic considerations drive migration across all age groups, economic opportunities play a significantly stronger role in the working-age population. In contrast, elderly individuals tend to prioritize environmental comfort in their destination choices and are less constrained by distance.