https://science.sciencemag.org/content/early/2020/09/11/science.abc8169.full.pdf
https://www.brookings.edu/techstream/how-do-recommender-systems-work-on-digital-platforms-social-media-recommendation-algorithms/
https://www.thelancet.com/action/showPdf?pii=S1473-3099%2821%2900648-4
https://cepr.org/sites/default/files/news/CovidEconomics19.pdf?utm_medium=email&utm_source=govdelivery#Paper2