A Social Security Administration study several years ago found that the life expectancy of male workers retiring at 65 had risen six years in the top half of the income distribution but only 1.3 years in the bottom half over the previous three decades.Over the past decade, as I already noted here, the life expectancy of poor white women has actually fallen, so these decade-old studies underestimate the problem.
In 1980, life expectancy at birth was 2.8 years longer for the highest socioeconomic group defined in a research study than the lowest, according to a report by the Congressional Budget Office. By 2000, the gap had grown to 4.5 years.
All of this boils down to economics: the richer you are, the longer you live, and as long as inequality keeps increasing, so will disparities in life expectancy.
If you think this is a problem we should try to solve (as I do), there are two possible approaches: either reduce income disparity, or move more of the economy into the public sphere and give the same stuff (healthcare, education, etc.) to everybody. Since nobody knows how to reduce income disparity, I think the only path toward a more equal society is through increased taxation and more government spending.