Socioeconomic differences – not genetics – account for the racial disparity in life expectancy, according to a new study by Princeton University researchers.
Variations in such factors as income, education and marital status contribute overwhelmingly to the health gap between black and white Americans, said researchers.
The study, published in the journal Democracy, said socioeconomic differences account for 80 percent of the life-expectancy divide between black and white men, and for 70 percent of the imbalance between black and white women.
Past research has linked mortality differences to certain socioeconomic disparities, but has not calculated the extent to which they affect life expectancy, said lead researcher Michael Geruso, a doctoral student in Princeton's Department of Economics.
For the study, Geruso and his colleagues examined Census Bureau death statistics and demographic and socioeconomic factors related to mortality. They concluded the average life expectancy as 71 for white men and 66 for black men. White and black women lived an average of 78 and 74 years, respectively.
They then examined racial differences in several factors -- family income, education, occupation, unemployment, urban residence, home ownership and marital status – and calculated the percentage each contributes to in life expectancy. For instance, income accounted for 52 percent of the life-expectancy difference between black and white men, and 59 percent of that for women – twice as high as any other single factor. For men, occupation explained 27 percent of the lifespan gap, versus 3 percent for women. Home ownership accounted for 23 percent of the female mortality difference, but only for 16 percent of the male gap.
"The most important contribution of this research is that it evaluates the relationship between socioeconomic status and racial gaps in mortality for almost all ages and using an unusually rich set of socioeconomic variables,” Geruso said. “It offers a precise, quantitative answer to a question many people are interested in: How much of the glaring disparities in life expectancy between blacks and whites might be explained by differences in a relatively small set of socioeconomic characteristics?”