Richer, better-educated people live longer than poorer, less-educated people. According to calculations from the National Longitudinal Mortality Survey which tracks the mortality of people originally interviewed in the CPS & other surveys, people whose relatives income in 1980 was greater than $50,000, putting them in the top five percent of incomes, had a life-expectancy at all ages that was about 25 percent longer than those in the bottom five percent, whose relatives income was less than $5,000. Lower mortality & morbidity is associated with any positive indicator of socioeconomic status, a relationship that has come to be known as "the gradient."
