How long can your baby expect to live?

By mid-January, a pile of  “Year in Review” magazines has accumulated beneath my coffee table. These dog-eared retrospectives all contain stories of a similar sort: famous people who died in 2013. The close of the calendar is a fitting time to reflect on icons who have departed, but what about the new arrivals? While we can’t predict the coming achievements of babies born in 2013, statistics on life expectancy at birth allow us to project on average how long they’ll live—estimates that vary dramatically according to the social, economic, and political circumstances they’re born into.   

Life expectancy at birth is defined by the World Health Organization as the “average number of years that a newborn is expected to live if current mortality rates continue to apply.” This means that the average age of death in the population a baby is born into is equivalent to the number of years they can be expected to live. This estimate, of course, does not account for future changes that might impact mortality rates during their lives (e.g., societal improvements or medical advances that could make them live longer, or climate changes or pandemics that could make them live shorter).  Life expectancy in the United States has improved dramatically over the past century—from 47.3 years in 1900 to 78.1 in 2008—due largely to public health advances such as sanitation, indoor plumbing, better working conditions, and immunizations.

Globally, it varies dramatically. Statistics from The World Bank show that life expectancy at birth is 45 years for a baby born in Sierra Leone and 82 years in Japan or Switzerland. Money explains some, but not all, of the difference. The U.S. is among the richest countries in the world and spends a substantially  greater portion of its gross domestic product on health care than do other members of the  Organization for Economic Cooperation and Development (OECD)—17.9 percent in 2011; the Netherlands was second-highest at 11 percent— but ranks 17th worldwide male life expectancy at birth and 16th for female.  As outlined in a recent Institute of Medicine report, issues such as early childhood poverty, built environments that promote automobile use and discourage physical activity, firearm deaths, comparatively limited access to primary care, and vast inequities in income and education all contribute to the nation’s lackluster showing.

Some of these same dynamics contribute to differences in the Philadelphia region. across the Delaware Valley.  The Institute for Health Metrics and Evaluation maintains an interactive map that shows life expectancy (and some other health measures) for males and females by state and county and how much it  changed from 1985 to 2010 (up 4.9 years for men/3.2 for women in Pennsylvania, 6.6 for men/4.5 for women in New Jersey). Life expectancy in 2010 for counties around the Philadelphia region: Philadelphia (71.5 years for men/78.4 years for women), Bucks (77.6/81.9), Chester (78.8/82.8), Delaware (75.1/80.4), Montgomery (78.2/82.2), Burlington (77.5/81.3), Camden (75.3/80), and Gloucester (75.9/80.5).

Besides the variation among geographic regions, life expectancy at birth differs among populations within them. In the U.S., racial disparities are pronounced and have persisted over time. A white male born in the U.S. between 1900 and 1902, for example, could expect to live 48.2 years while an African American male could only expect to live 32.5 years. In 2009, life expectancy at birth was 78.8 for a white baby but only 74.5 for an African American. In Philadelphia, an African American baby boy could expect to live 67.5 years while a white boy could expect to live 75.1 years and Asian boy 83.0 years.

The differences are not caused by race, which in fact  has been discredited as a biologically valid concept in health research, but rather by the social, economic, and political conditions that are correlated with skin color in this country. Indeed, it was these very conditions that W.E.B. DuBois observed when he published The Philadelphia Negro in 1899. As DuBois noted in a 1906 publication, “The high infantile mortality of Philadelphia today is not an [African American] affair, but an index of a social condition. ...The matter of sickness is an indication of social and economic position.” DuBois was a thinker ahead his time; we should think ahead and consider the implications of decisions we make today for babies who are born tomorrow.

Read more about The Public's Health.