Life Expectancy

Life expectancy is the number of years an individual is expected to live based on fixed demographic factors, such as year of birth, current age, geographic location, and gender. It is a statistical projection based on current death rates. Since 1840, global life expectancy at birth has grown fairly steadily—about 3 months per year. This smooth trend suggests that the combination of multiple advances in sanitation, nutrition, medicine, technology, and government have collectively influenced the observed improvement. The interesting questions for life-span development now revolve around matters of education, social structure, family life, stress and coping, and personality. That is, the focus is on longevity—who lives long and who dies young?

Public health organizations focus on life expectancy because it is the best single measure of ...