Socioeconomic Disparities and Health: Impacts and Pathways

Naoki Kondo

doi:10.2188/jea.je20110116

Abstract

Growing socioeconomic disparity is a global concern, as it could affect population health. The author and colleagues have investigated the health impacts of socioeconomic disparities as well as the pathways that underlie those disparities. Our meta-analysis found that a large population has risks of mortality and poor self-rated health that are attributable to income inequality. The study results also suggested the existence of threshold effects (ie, a threshold of income inequality over which the adverse impacts on health increase), period effects (ie, the potential for larger impacts in later years, specifically after the 1990s), and lag effects between income inequality and health outcomes. Our other studies using Japanese national representative survey data and a large-scale cohort study of Japanese older adults (AGES cohort) support the relative deprivation hypothesis, namely, that invidious social comparisons arising from relative deprivation in an unequal society adversely affect health. A study with a natural experiment design found that the socioeconomic gradient in self-rated health might actually have become shallower after the 1997–98 economic crisis in Japan, due to smaller health improvements among middle-class white-collar workers and middle/upper-income workers. In conclusion, income inequality might have adverse impacts on individual health, and psychosocial stress due to relative deprivation may partially explain those impacts. Any study of the effects of macroeconomic fluctuations on health disparities should also consider multiple potential pathways, including expanding income inequality, changes in the labor market, and erosion of social capital. Further studies are needed to attain a better understanding of the social determinants of health in a rapidly changing society.

Highlights

More than three-quarters of the countries belonging to the Organization for Economic Cooperation and Development (OECD) have experienced a growing gap between the rich and poor in the last 2 decades; in addition, growing socioeconomic disparity in the last 3 decades has become a global issue.[1]
We have investigated whether health disparities increased after the period of economic recession and expanding income inequality in Japan.[7,8]
Because we focused on the working-age population, we investigated individuals aged 20 to 60 years

Summary

Introduction

More than three-quarters of the countries belonging to the Organization for Economic Cooperation and Development (OECD) have experienced a growing gap between the rich and poor in the last 2 decades; in addition, growing socioeconomic disparity in the last 3 decades has become a global issue.[1]. We have conducted a number of studies that evaluated the contextual impacts of socioeconomic disparities on health and its psychosocial pathways.[2,3,5,6] We have investigated whether health disparities increased after the period of economic recession and expanding income inequality in Japan.[7,8]

Results

Conclusion