Population Aging, Demographic Metabolism, and the Rising Tide of Late Middle Age to Older Adult Loneliness around the World

Abstract

This study examines how population aging will shape a crucial aspect of mental health and social well-being - loneliness. Drawing on theories of demographic metabolism, United Nations' population estimates and projections, and survey data covering approximately 50% of the world's population aged 50 and above living in 27 countries, we estimate the role of population aging in shaping cross-national differences in loneliness from 1990 to 2050. We use survey data to estimate the prevalence of late middle age and older adult loneliness by age and sex, and then apply these rates to the evolving age and sex distributions of the populations. Our results highlight massive increases in loneliness at ages 50 and above with a tripling of the number of lonely adults in these age groups in our sample countries from 104.9 million in 1990 to 333.5 million in 2050, increasing variability across countries in the share of their populations composed of lonely adults 50 and above, and the feminization of global later life loneliness with an increasing share of lonely adults in these age ranges being women. These results illustrate the power of demographic modeling to advance understandings of national profiles of mental health and social well-being.

Figure 1.

Loneliness by Age and Cohort in Select Countries Note. See Appendix B for results for all countries.

Figure 2.

Comparing Observed and Modeled Late Middle Age and Older Adult Loneliness Prevalence in Focal Countries in Different Sample Years Note. See column 2 in Table 2 for country codes.

Figure 3.

Modeled Percent Changes from 1990 Late Middle Age and Older Adult Loneliness Prevalence by Country and Sex Note. See column 2 in Table 2 for country codes.

Figure 4.

Modeled Results for Number of Lonely Late Middle Age and Older Adults in All Sample Countries, by Sex and Broken Down by Age Group

Figure 5.

Modeled Changes in the Percent of Each Country Composed of Lonely Late Middle Age and Older Adults. Note. See column 2 in Table 2 for country codes.

Figure 6.

Modeled Changes in the Percent of Each Country Composed of Lonely Late Middle Age and Older Adults. Notes: Data are sorted by percent lonely late middle age and older adults in 2020. See column 2 in Table 2 for country codes.

Figure 7.

Sensitivity Analysis: Modeled Percent Changes from 1990 Late Middle Age and Older Adult Loneliness Prevalence by Country under Uncertainty Scenarios (Compare to Figure 3). Note. See column 2 in Table 2 for country codes.

Figure 8.

Sensitivity Analysis: Modeled Percent Changes from 1990 Late Middle Age and Older Adult Loneliness Prevalence by Country under SSP Demographic Models (Compare to Figure 3). Note. See column 2 in Table 2 for country codes. See Appendix B for greater detail.