The 1918 U.S. Infuenza Pandemic as a Natural Experiment, Revisited

Douglas Almond's use of the 1918 U.S. influenza pandemic as a natural experiment led to the seminal works on the subject of in utero health's impact on later life outcomes. The identification strength and clarity of his work, though, is driven by the inherent natural experiment supposition of random assignment. By using data from the 1920 and 1930 U.S. census, this study investigates this keystone assumption and shows that the families of the "treatment" cohort used by Douglas Almond were significantly less literate and economically prosperous than the families of the "control" group. The first order effect of parents' education and wealth on a child's long-run SES and health conditions eliminates Almond's ability to make direct inference on fetal health's impact on one's long-term well being using the 1918 U.S. influenza pandemic.