Nils C. Wernerfelt
Institutional Affiliation: Facebook
NBER Working Papers and Publications
|October 2014||Second Trimester Sunlight and Asthma: Evidence from Two Independent Studies|
with David Slusky, Richard Zeckhauser: w20599
One in twelve Americans suffers from asthma and its annual costs are estimated to exceed $50 billion. Simultaneously, the root causes of the disease remain unknown. A recent hypothesis speculates that maternal vitamin D levels during pregnancy affect the probability the fetus later develops asthma. In two large-scale studies, we test this hypothesis using a natural experiment afforded by historical variation in sunlight, a major source of vitamin D. Specifically, holding the birth location and month fixed, we see how exogenous within-location variation in sunlight across birth years affects the probability of asthma onset. We show that this measurement of sunlight correlates with actual exposure, and consistent with pre-existing results from the fetal development literature, we find substa...
Published: Nils Wernerfelt & David J. G. Slusky & Richard Zeckhauser, 2017. "Second Trimester Sunlight and Asthma: Evidence from Two Independent Studies," American Journal of Health Economics, vol 3(2), pages 227-253. citation courtesy of