(Data provided by Jay Olshansky of the University of Illinois in Chicago)

Look at this chart, and weep.

It compares the life expectancy of women at the bottom of the income ladder to those at the top. Birth certificates do not record information about income, but researchers use race and educational status as proxies. In 1990, the life expectancy of a woman who never completes high school was 77.7 years. The life expectancy of a woman who completes college was 80 years. That makes for a difference of 2.3 years. By 2010, despite all the advances in medicine, the woman who never completes high school is expected to die sooner, at 77.3 years of age. But the woman who completes college is expected to live much longer,  to 83.9 years of age. That's a gap of 6.6 years.

Add it all up, and the gap in life expectancy between a disadvantaged woman and an advantaged woman has almost tripled over the past 20 years. Yes, growing inequality of income in America seems to mean growing inequality of death.

You can see it in the chart above. The blue bars show life expectancy of disadvantaged socioeconomic groups. The orange bars show life expectancy of advantaged groups. The gray patterned bars, modeled on the secondary Y-axis, measure the gap.

All hope is not lost, though. While inequality of death is increasing, inequality of birth is declining — a topic examined in a Washington Post story today. The reasons are many: improving access to care, nutritional assistance, less pollution, efforts to stem violence at home.

A study by Janet Currie of Princeton found that in 1989, one in six babies born to economically challenged women weighed less than the 5 1/2 pounds that doctors consider healthy — compared with one in 32 babies born to the more advantaged group. Over the following 20 years, the study found improvements for the less advantaged group, with the odds of having an unhealthy baby falling close to one in eight. The rate was essentially unchanged for more advantaged women. (It increased slightly among wealthier women likely because of more use of fertility treatments.)

The data are illustrated below:

(Data provided by Janet Currie of Princeton University)

Given that the disadvantages of being born at an unhealthy weight can linger for a lifetime, if we can make further improvements in this chart, we might also be able to tackle inequality of death.