An Example of Early Life Damage Affecting Longevity
Per the reliability theory of aging, we should expect to see shorter life expectancies result from damage or stress in early life. Here, a historical analysis supports that line of thinking: "Nutritional conditions in utero and during infancy may causally affect health and mortality during childhood, adulthood, and at old ages. This paper investigates whether exposure to a nutritional shock in early life negatively affects survival at older ages, using individual data. Nutritional conditions are captured by exposure to the Potato famine in the Netherlands in 1846-1847, and by regional and temporal variation in market prices of potato and rye. The data cover the lifetimes of a random sample of Dutch individuals born between 1812 and 1902 and provide individual information on life events and demographic and socioeconomic characteristics. First we non-parametrically compare the total and residual lifetimes of individuals exposed and not exposed to the famine in utero and/or until age 1. Next, we estimate survival models in which we control for individual characteristics and additional (early life) determinants of mortality. We find strong evidence for long-run effects of exposure to the Potato famine. The results are stronger for boys than for girls. Boys and girls lose on average 4, respectively 2.5 years of life after age 50 after exposure at birth to the Potato famine. Lower social classes appear to be more affected by early life exposure to the Potato famine than higher social classes. These results confirm the mechanism linking early life (nutritional) conditions to old-age mortality."