[영문]We use the core interviews of the US Health Interview Survey for the years 1987?1994, to study the effects of socioeconomic status (SES) on mortality and self-reported health. We find, consistent with previous studies, that the relationship between mortality and indicators such as education and income diminishes with age. We consider new explanations for this result and conclude that general biological deterioration at old age is probably the principal one. One important piece of evidence for this conclusion is the finding that there is no relationship at all between mortality and SES for people whose self-reported health status at baseline is either fair or poor.