Average life expectancy has been increasing more or less steadily for years, but researchers at the center found that people with a lower socioeconomic status, or SES, tend not to live as long.
In addition, while all groups are living longer, the life-expectancy gap between the lowest SES groups and the highest has widened since 1979. As a result, for men in the lowest SES quartile to even maintain the same share of their lives in retirement as they had in 1979, they would retire at 68.1 years of age, compared to 69.6 for the top male quartile. (For women in the lowest quartile, retirement would need to come at age 66, compared to 67.2 for the top quartile.)
The authors were writing about longevity and retirement age, not Social Security claiming, but it is clear that a significant share of people over age 65 rely heavily on the program. According to the Social Security Administration, 21 percent of elderly couples and 46 percent of elderly unmarried counted on Social Security for 90 percent of their income in 2013, the latest data available.