Unlocking the inverted-U: exploring the threshold impact of population aging on income inequality dynamics
DOI: https://doi.org/10.3846/tede.2025.23762Abstract
As population aging unfolds at an unprecedented scale worldwide, its impact on income inequality continues to be contentious, with no clear consensus in the literature. Rather than viewing the aging-inequality linkage as solely positive or negative, this paper introduces a modified life cycle with precautionary behavior, indicating that inequality may initially worsen with aging before stabilizing at later stages. The Dynamic Panel Threshold Kink (DPTK) regression method is used to identify the threshold point of aging intensity at which the inequality begins to moderate following a period of intensification. The findings reveal a threshold aging intensity of 1.4%, which supports an inverted-U characterization of the aging-inequality nexus. The results suggest that liberalizing trade and improving government redistribution can assist countries experiencing a rise in inequality. At the same time, the prevalence of precautionary effects due to population aging may offer a natural defense against the detrimental effects of inequality over time.
First published online 05 June 2025
Keywords:
income inequality, population aging, panel data, kink threshold regressionHow to Cite
Share
License
Copyright (c) 2025 The Author(s). Published by Vilnius Gediminas Technical University.
This work is licensed under a Creative Commons Attribution 4.0 International License.
References
Alimi, O. B., Maré, D. C., & Poot, J. (2017). More pensioners, less income inequality? The impact of changing age composition on inequality in big cities and elsewhere (IZA Discussion Paper No.10690). https://doi.org/10.2139/ssrn.2956785
Anderson, E., Jalles D’Orey, M. A., Duvendack, M., & Esposito, L. (2017). Does government spending affect income inequality? A meta-regression analysis. Journal of Economic Surveys, 31(4), 961–987. https://doi.org/10.1111/joes.12173
Andriopoulou, E., Karakitsios, A., & Tsakloglou, P. (2017). Inequality and poverty in Greece: Changes in times of crisis (IZA Discussion Paper No. 11006). https://doi.org/10.2139/ssrn.3041802
Antonelli, C., & Gehringer, A. (2017). Technological change, rent and income inequalities: A Schumpeterian approach. Technological Forecasting and Social Change, 115, 85–98. https://doi.org/10.1016/j.techfore.2016.09.023
Arellano, M., & Bover, O. (1995). Another look at the instrumental variable estimation of error-components models. Journal of Econometrics, 68(1), 29–51. https://doi.org/10.1016/0304-4076(94)01642-D
Aydin, C., & Esen, Ö. (2018). Reducing CO2 emissions in the EU member states: Do environmental taxes work? Journal of Environmental Planning and Management, 61(13), 2396–2420. https://doi.org/10.1080/09640568.2017.1395731
Barreti, G. F., Crossley, T. F., & Worswick, C. (2000). Demographic trends and consumption inequality in Australia between 1975 and 1993. Review of Income and Wealth, 46(4), 437–456. https://doi.org/10.1111/j.1475-4991.2000.tb00410.x
Bhattacharyya, A. K. (1975). Income inequality and fertility: A comparative view. Population Studies, 29(1), 5–19. https://doi.org/10.1080/00324728.1975.10410181
Bloom, D. E., Canning, D., & Fink, G. (2010). Implications of population ageing for economic growth. Oxford Review of Economic Policy, 26(4), 583–612. https://doi.org/10.1093/oxrep/grq038
Boar, C. (2020). Dynastic precautionary savings (NBER Working Paper No. 26635). National Bureau of Economic Research. https://doi.org/10.3386/w26635
Cameron, L. A. (2000). Poverty and inequality in Java: Examining the impact of the changing age, educational and industrial structure. Journal of Development Economics, 62, 149–180. https://doi.org/10.1016/S0304-3878(00)00079-1
Chen, X., Huang, B., & Li, S. (2017). Population aging and inequality: Evidence from the People’s Republic of China (ADBI Working Paper No. 794). Asian Development Bank Institute.
Choi, I. (2001). Unit root tests for panel data. Journal of International Money and Finance, 20(2), 249–272. https://doi.org/10.1016/S0261-5606(00)00048-6
Chong, T. T. L., & Ka, Y. T. (2019). Forecasting income inequality with demographic projections (MPRA Paper No. 99160). University Library of Munich, Germany.
Crowe, C. (2004). Inflation, inequality and social conflict (CEP Discussion Paper No. 657). Centre for Economic Performance.
Danziger, S., van der Gaag, J., Smolensky, E., & Taussig, M. K. (1982). The life-cycle hypothesis and the consumption behavior of the elderly. Journal of Post Keynesian Economics, 5(2), 208–227. https://doi.org/10.1080/01603477.1982.11489357
Dolls, M., Doorley, K., Paulus, A., Schneider, H., & Sommer, E. (2019). Demographic change and the European income distribution. Journal of Economic Inequality, 17, 337–357. https://doi.org/10.1007/s10888-019-09411-z
Dong, Z., Tang, C., & Wei, X. (2018). Does population aging intensify income inequality? Evidence from China. Journal of the Asia Pacific Economy, 23(1), 66–77. https://doi.org/10.1080/13547860.2017.1354270
Elinder, M., Erixson, O., & Waldenström, D. (2018). Inheritance and wealth inequality: Evidence from population registers. Journal of Public Economics, 165, 17–30. https://doi.org/10.1016/j.jpubeco.2018.06.012
Ferjani, S., Saafi, S., & Nouira, R. (2023). Will substantial revaluation of Chinese currency be helpful in attenuating the United States’ trade deficit with China? New evidence from the dynamic threshold kink model. The International Trade Journal, 1–25. https://doi.org/10.1080/08853908.2023.2236220
Goh, S. K., McNown, R., & Wong, K. N. (2020). Macroeconomic implications of population aging: Evidence from Japan. Journal of Asian Economics, 68, Article 101198. https://doi.org/10.1016/j.asieco.2020.101198
Hansen, B. E. (1999). Threshold effects in non-dynamic panels: Estimation, testing, and inference. Journal of Econometrics, 93(2), 345–368. https://doi.org/10.1016/S0304-4076(99)00025-1
Haq, M., Badshah, I., & Ahmad, I. (2016). Does globalisation shape income inequality? Empirical evidence from selected developing countries. Pakistan Development Review, 251–270.
Hong, B. E., & Kim, H. Y. (2012). Trends of income inequality among the elderly in Korea. Asian Social Work and Policy Review, 6(1), 40–55. https://doi.org/10.1111/j.1753-1411.2011.00062.x
Hwang, S., Choe, C., & Choi, K. (2021). Population ageing and income inequality. Journal of the Economics of Ageing, 20, Article 100345. https://doi.org/10.1016/j.jeoa.2021.100345
Im, K. S., Pesaran, M. H., & Shin, Y. (2003). Testing for unit roots in heterogeneous panels. Journal of Econometrics, 115(1), 53–74. https://doi.org/10.1016/S0304-4076(03)00092-7
Jain-Chandra, S., Kinda, T., Kochhar, K., Piao, S., & Schauer, J. (2016). Sharing the growth dividend: Analysis of inequality in Asia (IMF Working Paper No. 16/48).
Jäntti, M. (1997). Inequality in five countries in the 1980s: The role of demographic shifts, markets and government policies. Economica, 64(255), 415–455. https://doi.org/10.1111/1468-0335.00088
Jenkins, S. P. (1995). Accounting for inequality trends: Decomposition analyses for the UK, 1971–86. Economica, 62(245), 29–63. https://doi.org/10.2307/2554775
Kang, S. J., & Rudolf, R. (2016). Rising or falling inequality in Korea? Population aging and generational trends. Singapore Economic Review, 61(5), Article 1550089. https://doi.org/10.1142/S0217590815500897
Khera, P., & Gao, Y. (2024). Sustainable path to inclusive growth in Japan: How to tackle income inequality? (IMF Selected Issue Paper No. SIP/2024/026). https://doi.org/10.5089/9798400282232.018
Kremer, S., Bick, A., & Nautz, D. (2013). Inflation and growth: New evidence from a dynamic panel threshold analysis. Empirical Economics, 44, 861–878. https://doi.org/10.1007/s00181-012-0553-9
Kuznets, S. (1955). Economic growth and income inequality. American Economic Review, 45(1), 1–28.
Lam, D., & Levison, D. (1992). Age, experience, and schooling: Decomposing earnings inequality in the United States and Brazil. Sociological Inquiry, 62(2), 220–245. https://doi.org/10.1111/j.1475-682X.1992.tb00195.x
Lee, R., & Mason, A. (2014). Is low fertility really a problem? Population aging, dependency, and consumption. Science, 346(6206), 229–233.
Lee, S.-H., Mason, A., & Park, D. (2011). Why does population aging matter so much for Asia? Population aging, economic growth, and economic security in Asia (ADB Economics Working Paper No. 284). Asian Development Bank. http://ssrn.com/abstract=1960877
Lu, X., & White, H. (2014). Robustness checks and robustness tests in applied economics. Journal of Econometrics, 178(1), 194–206. https://doi.org/10.1016/j.jeconom.2013.08.016
Luo, Z., Wan, G., Wang, C., & Zhang, X. (2018). Aging and inequality: The link and transmission mechanisms. Review of Development Economics, 22(3), 885–903. https://doi.org/10.1111/rode.12394
Maddah, M., Nejad, A. H. G., & Sargolzaei, M. (2022). Natural resources, political competition, and economic growth: An empirical evidence from dynamic panel threshold kink analysis in Iranian provinces. Resources Policy, 78, Article 102928. https://doi.org/10.1016/j.resourpol.2022.102928
Nord, S. (1980). An empirical analysis of income inequality and city size. Southern Economic Journal, 46(3), 863–872. https://doi.org/10.2307/1057154
Ohtake, F., & Saito, M. (1998). Population aging and consumption inequality in Japan. Review of Income and Wealth Series, 44(3), 361–381. https://doi.org/10.1111/j.1475-4991.1998.tb00287.x
Okunade, S. O. (2022). Institutional threshold in the nexus between financial openness and TFP in Africa: A dynamic panel analysis. Social Sciences & Humanities Open, 5(1), Article 100245. https://doi.org/10.1016/j.ssaho.2021.100245
Pesaran, M. H. (2004). General diagnostic tests for cross section dependence in panels (CEsifo Working Paper No. 1229; IZA Discussion Paper No. 1240). https://doi.org/10.2139/ssrn.572504
Saffarudin, M. R. S., Goh, S. K., Wong, K. N., & Law, C. H. (2024). The impact of social globalization on domestic savings: A long-run macroeconomic analysis of advanced ageing economies in the Asia-Pacific Region. Applied Economics, 1–14. https://doi.org/10.1080/00036846.2024.2379510
Scott, A. J. (2021). The longevity society. The Lancet Healthy Longevity, 2(12), e820–e827. https://doi.org/10.1016/S2666-7568(21)00247-6
Seo, M. H., & Shin, Y. (2016). Dynamic panels with threshold effect AND endogeneity. Journal of Econometrics, 195(2), 169–186. https://doi.org/10.1016/j.jeconom.2016.03.005
Seo, M. H., Kim, S., & Kim, Y. J. (2019). Estimation of dynamic panel threshold model using Stata. Stata Journal, 19(3), 685–697. https://doi.org/10.1177/1536867X19874243
Shaik, M. R., Goh S. K., Wong, K. N., & Law, C. H. (2023). Does population aging coexist with income inequality in the long run? Evidence from selected Asia-Pacific countries. Economic Systems, 48, Article 101149. https://doi.org/10.1016/j.ecosys.2023.101149
Shen, C., & Zhao, X. (2023). How does income inequality affects economic growth at different income levels? Economic Research – Ekonomska Istrazivanja, 36(1), 864–884. https://doi.org/10.1080/1331677X.2022.2080742
Solt, F. (2020). Measuring income inequality across countries and over time: The Standardized World Income Inequality Database. Social Science Quarterly, 101(3), 1183–1199. https://doi.org/10.1111/ssqu.12795
Steiner, F. (2001). Regulation, industry structure and performance in the electricity supply industry (OECD Economic Department Working Paper No. 238). http://doi.org/10.2139/ssrn.223648
Tsionas, M. (2019). Panel data econometrics. Academic Press.
United Nations. (n.d.). Regional groups of member States. https://www.un.org/dgacm/en/content/regional-groups
University of Texas at Austin. (2015). Estimated Household Income Inequality (EHII) [Data set]. http://www.utip.lbj.utexas.edu/data/UtipUnidoEhiiV2017_v.1.xlsx
Westerheide, P. (2005). Auswirkungen von Erbschaften und Schenkungen auf die Vermögensbildung privater Personen und Haushalte [The importance of intergenerational transfers for private wealth accumulation: An empirical analysis of German survey data]. Jahrbücher für Nationalökonomie und Statistik, 225(4), 459–481. https://doi.org/10.1515/jbnst-2005-0407
World Bank. (n.d.). World development indicators [Data set]. https://databank.worldbank.org/source/world-development-indicators
World Inequality Database. (n.d.). https://wid.world/data/
Yu, S., Liu, J., Hu, X., & Tian, P. (2022). Does development of renewable energy reduce energy intensity? Evidence from 82 countries. Technological Forecasting and Social Change, 174, Article 121254. https://doi.org/10.1016/j.techfore.2021.121254
Zhang, Y., Parker, D., & Kirkpatrick, C. (2005). Competition, regulation and privatization of electricity generation in developing countries: Does the sequencing of the reforms matter? Quarterly Review of Economics and Finance, 54(2–3), 358–379. https://doi.org/10.1016/j.qref.2004.12.009
Zhang, H., Ke, L., & Ding, D. (2021). The effect of Chinese population aging on income inequality: Based on a micro-macro multiregional dynamic CGE modelling analysis. Emerging Markets Finance and Trade, 57(5), 1399–1419. https://doi.org/10.1080/1540496X.2019.1623781
Zhong, H. (2011). The impact of population aging on income inequality in developing countries: Evidence from Rural China. China Economic Review, 22(1), 98–107. https://doi.org/10.1016/j.chieco.2010.09.003
View article in other formats
Published
Issue
Section
Copyright
Copyright (c) 2025 The Author(s). Published by Vilnius Gediminas Technical University.
License
This work is licensed under a Creative Commons Attribution 4.0 International License.