Kristen Lewis and Sarah Burd-Sharps are co-directors of the American Human Development Project.

America experienced great progress in human well-being in the last half century. A baby born in 2005 will live, on average, eight years longer than one born in 1960. High school completion rates have doubled, and the percentage of college graduates has almost quadrupled. The typical American earned almost twice as much in 2005 as in 1960 (in 2005 dollars).

But these averages – as averages are wont to do – hide a world of variation, as well as just how much certain groups have been left behind in that path toward progress. Manhattan’s East Side and the South Bronx, for example, are five subway stops and little more than two miles apart, but going from one neighborhood to the other is a trip back in time in terms of human development.

Recent Economix posts have referred to the work of the American Human Development Project in discussions centering on the value of the human development index. The folks at Economix have kindly given us an opportunity to share some of our findings.

In 2008, we constructed a first-ever American Human Development Index to assess the relative well-being of different groups of Americans. Our index is not comparable to the global Human Development Index produced by the U.N. Development Program, a measure that looks at the social and economic development of different countries. The U.N. index, which is rooted in the work of the Nobel Laureate Amartya Sen, was, however, the model for our index.

The American Human Development Index combines official American government data on health, education and income into a single, composite measure. Health is measured by life expectancy; education by a combination of educational attainment and school enrollment; and income by median personal earnings (wages and salaries). The value of having a single number is that it allows for methodologically sound yet easily understood comparisons among different population groups. We ranked the American population in terms of well-being by state, by congressional district, by the five major racial/ethnic categories of the Census Bureau, and by gender.

In addition, using the same indicators, we calculated a historic index for the country as a whole for every decade from 1960 onwards.

What did we find?

In the state index, Connecticut was at the top and Mississippi was at the bottom. While their ranks may not surprise you – isn’t Mississippi always at the bottom of these sorts of lists? – the size of the gap might. Connecticut has an H.D. index of 6.37 (on a scale of 0 to 10), which, if current trends continue, will be the average of America as a whole in the year 2020. Mississippi, on the other hand, has an H.D. index (3.58) lower than that of the whole country some 20 years ago.

Nearly three decades, a generation of progress, separate the two states.

In terms of health, African-Americans today have a lifespan shorter than the average American in the late 1970s, three decades ago. African-American men live shorter lives today than the average American in 1960. The life expectancy today in Kentucky’s 5th District (the southeastern part of the state) is below that of the United States as a whole 30 years ago.

When it comes to education, the percentage of the adult population in Texas’s 29th District (the Houston area) that did not complete high school — close to half — is at about the level of the United States average in the mid-1960s. Nationwide, Latinos have the lowest ranking for education — roughly 40 percent of Latinos age 25 and up don’t have a high school diploma, about the same rate as America as a whole in the mid-1970s.

Looking at income, our index shows that Latina women earn, on average, about $16,000, compared to white and Asian-American men, who earn about $37,000. Taking another look at Mississippi, we see that not everyone in the state is struggling. White men earn about $5,000 more than the typical American worker today — but white women earn the same wage as an average American in 1980, African-American men earn 1970 wages, and African-American women pre-1960 wages.

As for our original example, that of the East Side versus the Bronx, it seems the East Side is ahead of its time.

Given the historic growth pattern from 1960 to 2005, the United States as a whole won’t have levels of well-being typical of the East Side today until 2041, whereas residents of the South Bronx have levels of health, education and income typical of Americans in the mid-1980s. On average, a resident of Manhattan’s 14th Congressional District (the East Side) earns two and a half times as much, lives four years longer, and is seven times more likely to have a college degree than a resident of the 16th District (the South Bronx).

Human development is about what ordinary people can do and what they can become, about the liberty they have to exercise real choice in their lives. For most Americans, the last half-century has brought greater freedom, opportunity and well-being. But the American Human Development Index tells us that huge segments of society are being left out. And it offers a tool to hold leaders accountable for investing in an infrastructure of opportunity that better serves the next generation.