How spatial fixity of individual daily activities evolves in the long-term: A life course and multi-scale behavior explanation

Spatial fixity, measuring the extent to which individual activities are confined to specific locations, is central to geographical studies on daily activities. Although recent studies have identified factors contributing to the variability of daily activity spatial fixity, there is a dearth of longitudinal observations to understand its evolution over extended timeframes. Addressing this research gap, the study introduces a framework that integrates multi-scale individual behaviors to investigate the long-term evolution of peoples daily activity spatial fixity, offering insights from a life course perspective. Using mobile phone data of 290,679 individuals across different age groups, the study assessed changes in their activity patterns from October 2019 to October 2020 and from October 2019 to May 2023. Three major findings were derived from Difference-in-Difference modeling and behavior grouping: (1) Individual daily activity spatial fixity exhibit a U-shaped distribution with age, revealing the 30–34 age group with the lowest fixity. Consistent levels of spatial fixity are observed as time progresses and individuals transition into specific age stages. (2) The multi-scale behavior framework elucidates over 40 % of the variation in daily activity spatial fixity over one and four-year intervals, and the result highlights the significance of integrating higher-scale behavioral dynamics over extended period. (3) Distinct behavioral change trends before and after the age of 35 result in the U-shaped curve of spatial fixity evolution. The study advances our comprehension of the long-term dynamics of human mobility. The findings provide valuable insights for enhancing individual behavior modeling, addressing delays in demographic data collection, and informing targeted social policies.