Author Affiliations: Division of Health Research, Lancaster University, Lancaster, England; and Faculty of Health Sciences, University of Sydney, Sydney, Australia.
Abundant evidence now suggests that living in relative poverty and exposure to relative income inequality, especially in childhood, may have a detrimental influence on health and well-being during childhood and across the life course. This Commentary discusses the importance of relative poverty in childhood and the implications of income inequality for population health.
Child relative poverty (ie, children living in a household with relative income poverty) appears to be a potentially important indicator for children's health. Relative income poverty is commonly defined as having equivalized household income of less than 50% of the national median.1 Equivalization is calculated by dividing household income by an indicator of household composition or need, for example, the square root of the number of individuals living in the household.2 Child relative poverty is strongly related to overall income inequality as measured by the Gini coefficient, which reflects inequalities in the distribution of income and wealth for the population of a nation; a lower Gini coefficient suggests more equal income or wealth distribution, whereas a high Gini coefficient reflects more unequal distribution of income and wealth.3 For instance, the United States has both the highest national wealth and the highest Gini coefficient.3 Thus, in the United States, as with many of the world's richest countries, there is little or no association between national wealth and the levels of income inequality evident within those nations.
Emerson E. Relative Child Poverty, Income Inequality, Wealth, and Health. JAMA. 2009;301(4):425-426. doi:10.1001/jama.2009.8