Data and Code for: Health effects of cousin marriage: Evidence from U.S. genealogical records

Cousin marriage rates are high in many countries today. We provide the first estimate of the effect of such marriages on the life expectancy of offspring. By studying couples married over a century ago, we can observe their offspring across the lifespan. US genealogical data allows us to identify children whose parents were first cousins, and compare their years of life to the offspring of their parents’ siblings. Marrying a cousin leads to more than a two-year reduction in age-5 life expectancy. This effect is strikingly stable across time, despite large changes in life expectancy and economicenvironment.