Working Paper: NBER ID: w9933
Authors: Dora L. Costa; Joanna Lahey
Abstract: We argue that the environment determines life span, using historical data to show that such indicators of environmental insults in early childhood and young adulthood as quarter of birth, residence, occupation, wealth, and the incidence of specific infectious diseases affected older age mortality. Consistent with improvements in early life factors, we find that the effect of quarter of birth on older age mortality has diminished over the twentieth century and that the declining impact of quarter of birth explains 16 to 17 percent of the difference in ten year mortality rates of Americans age 60-79 in 1900 and in 1960-1980. We estimate that at least one-fifth of the increase between 1900 and 1999 in the probability of a 65 year old surviving to age 85 may be attributable to early life conditions. We also present suggestive evidence on the mortality trajectory of the oldest old in the first half of the twentieth century that implies that the shape of the mortality trajectory, though not its level, has remained constant.
Keywords: longevity; mortality; environmental factors; historical data
JEL Codes: I12; J11; N30
Edges that are evidenced by causal inference methods are in orange, and the rest are in light blue.
| Cause | Effect |
|---|---|
| environmental insults during early childhood and young adulthood (I12) | mortality in older age (J26) |
| quarter of birth (J13) | mortality in older age (J26) |
| diminishing effect of quarter of birth on mortality rates (J11) | difference in ten-year mortality rates for individuals aged 60-79 (I14) |
| improved early life conditions (I15) | increase in the probability of a 65-year-old surviving to age 85 (I14) |
| mortality trajectory of the oldest old (J26) | changes in mortality levels (I12) |