There have been many studies concerned with the factors that account for longevity, but most that have looked at location or geography, work history, family structure, church attendance and friendship networks were not rigorous. In America, the rich live longer than the poor, and Caucasians longer than African-Americans, but this is also a demographic fact, not an explanation about what causes longevity.
For a long time both educational researchers and health economists have thought that there must be a link between formal schooling and longevity. The hypothesis is that a few extra years in school adds more years of life and a healthier time as senior citizens.
There have been small-scale studies in the past that have suggested that the relationship existed between number of years of schooling, general health and longevity. In Botswana, it has been found that primary school teachers were more likely to die of AIDS than secondary school teachers, and that tertiary instructors are even less likely.
Now a graduate student at Columbia University in New York City, Adriana Lleras-Muney, has found what is the critical factor contributing to longevity. Much of this may seem like common sense, but there is more to it. In each nation there are records for "average life spans" and on the different subsets related to location, religion, occupation and level of education.
