Nils C. Wernerfelt
1 Hacker Way
Institutional Affiliation: Facebook
NBER Working Papers and Publications
|September 2020||The Effects of COVID-19 on U.S. Small Businesses: Evidence from Owners, Managers, and Employees|
with , , , , , : w27833
We analyze a large-scale survey of owners, managers, and employees of small businesses in the United States to understand the effects of the early stages of the COVID-19 pandemic on those businesses. The survey was fielded in late April 2020 among Facebook business page administrators, frequent sellers on Facebook's e-commerce platform Marketplace, and the general Facebook user population. We observe more than 66,000 responses covering most sectors of the economy, including many businesses that had stopped operating due to the pandemic. The survey asks 136 questions covering topics such as changes in business operations and employment, changes in financing patterns, and the interaction of household and business responsibilities. We characterize the adjustments implemented to survive the pa...
|October 2014||Second Trimester Sunlight and Asthma: Evidence from Two Independent Studies|
with , : 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