Sunlight and Protection Against Influenza

David Slusky and Richard Zeckhauser

Working Paper Series from Harvard University, John F. Kennedy School of Government

Abstract: 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 within states and during the same calendar month, affect influenza incidence. We find that sunlight strongly protects against influenza. This relationship is driven by sunlight in late summer and early fall, when there are sufficient quantities of both sunlight and influenza activity. A 10% increase in relative sunlight decreases the influenza index in September by 3 points on a 10-point scale. This effect is far greater than the effect of vitamin D supplementation in randomized trials, a differential due to broad exposure to sunlight, hence herd immunity. We also find suggestive evidence, consistent with herd immunity theory, that the protective sunlight effect is strongest with a middle level of population density.

JEL-codes: I10 I12 I18 (search for similar items in EconPapers)
Date: 2018-02
New Economics Papers: this item is included in nep-hea
References: View references in EconPapers View complete reference list from CitEc
Citations: View citations in EconPapers (13)

Downloads: (external link)
https://research.hks.harvard.edu/publications/getFile.aspx?Id=1654

Related works:
Journal Article: Sunlight and Protection Against Influenza (2021)
Working Paper: Sunlight and Protection Against Influenza (2020)
Working Paper: Sunlight and Protection Against Influenza (2018)
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:ecl:harjfk:rwp18-007

Access Statistics for this paper

More papers in Working Paper Series from Harvard University, John F. Kennedy School of Government Contact information at EDIRC.
Bibliographic data for series maintained by ().