THE SHAPE OF THE RELATIONSHIP BETWEEN INCOME AND MORTALITY IN THE UNITED-STATES - EVIDENCE FROM THE NATIONAL LONGITUDINAL MORTALITY STUDY

A follow-up study based on a large national sample was used to examine differences in the well-established inverse gradient between income a nd mortality at different income levels. The study showed the income-m ortality gradient to be much smaller at high income levels than at low to moderate income levels in the working age (25 to 64 years) and eld erly (over 65 years) populations for men and women both before and aft er adjustment for other socioeconomic variables. In addition, a much l arger gradient existed for working age women at extreme poverty levels than for those women at low to moderate income levels. The income-mor tality gradient was much smaller in the elderly than in the working ag e population. The study also examined the ability of several different mathematic functions of income to delineate the relationship between income and mortality. The study suggested that the health benefits ass ociated with increased income diminish as income increases.