Sunlight and Protection Against Influenza
Recent medical literature suggests that vitamin D supplementation protects against acute respiratory tract infection. Humans exposed to sunlight produce vitamin D directly. This paper investigates how differences in sunlight, as measured over several years across states and during the same calendar week, affect influenza incidence. We find that sunlight strongly protects against getting influenza. This relationship is driven almost entirely by the severe H1N1 epidemic in fall 2009. A 10% increase in relative sunlight decreases the influenza index in September or October by 1.1 points on a 10-point scale. A second, complementary study employs a separate data set to study flu incidence in counties in New York State. The results are strongly in accord.
We thank Nils C. Wernerfelt for exceptional advice and guidance throughout this project. We are also immensely grateful to Janet Currie and Diane Alexander for their help in implementing their geographically granular influenza measure, to Mark Anderson and Dan Rees for providing their early twentieth century mortality data, and to Corey White for sharing his data on the influenza vaccine match rates by season. We also thank Susan Graber, Ryan Brown, and conference participants at the 2018 American Society of Health Economists conference for their comments and suggestions. We are especially grateful to two anonymous referees who provided extensive and insightful comments and suggestions. The views expressed herein are those of the authors and do not necessarily reflect the views of the National Bureau of Economic Research.
- Influenza, a highly contagious viral infection, is a major public health hazard. Influenza and pneumonia (which may occur in...
David J.G. Slusky & Richard J. Zeckhauser, 2020. "Sunlight and Protection Against Influenza," Economics & Human Biology, .