Increasing mobility is linked to decreasing cohesion of personal networks overthe lifecourse of an entire population

On October 18, Eszter Bokányi will present her work on “Increasing mobility is linked to decreasing cohesion of personal networks over the lifecourse of an entire population” at the Dutch NetSci Symposium, which will take place at Eindhoven University of Technology.

Abstract

Growing accessibility between places and a changing society foster higher human mobility both daily and long-term, which results in an increased social connectivity between faraway places. Thus, geographic displacement creates new connections and at the same time rearranges the existing spatial structure of social networks. Both of these mechanisms are little understood in the existing literature of social network formation processes. Moreover, up until now, it has also been a challenge to systematically follow the temporal evolution of an entire population’s social network structure.

In this work, we use a unique longitudinal population-scale network dataset sourced from Statistics Netherlands. This network contains family, work, school, household, and next-door neighbor connections derived from administrative registers, that together constitute a multilayer social opportunity structure for all residents of the Netherlands between 2009 and 2022. We follow the patterns of individuals’ network surroundings over time, and measure size, closure, and geographical dispersion of ego networks. Size is captured by degree, closure by excess closure [1], which is based on the node clustering coefficient. Geographical dispersion is given by the average distance from network neighbors, and the average share of network neighbors in the same municipality or the same next-door neighborhood as the ego.

The three findings presented in this work are that while the average size of ego networks stays stable over the observed period, average closure drops by as much as 10%, and the average distance from network neighbors grows, while the average share of network neighbors in the same geographic area decreases. We use multivariate regressions to show that the observed decrease in the closure is significantly linked to the growing geographic dispersion, thus, the increasing daily and long-term mobility of people. We control for demographic and socio-economic background including the age, migrant generation, income, and whether people attend school and have employment. The regressions confirm that beyond degree and demographics, variables that capture people’s mobility are linked to the opening up of individual networks.

This work is the first of its kind that aims to map the temporal network of an entire population structure comprehensively. As such, it offers a starting point for a wide variety of impactful network science research at the level of a complete population.

[1] Bokányi, E., Heemskerk, E. M., & Takes, F. W. (2023). The anatomy of a population-scale social network. Scientific Reports, 13(1), 9209.