Precaution, Social Distancing and Tests in a Model of Epidemic Disease

Abstract

Abstract I develop an extension of a canonical epidemiology model in which the policy in place determines the probability of transmission of an epidemic disease during economic and social interaction. I use the model to evaluate the effects of isolating symptomatic individuals, of increasing social distancing and of tests such as polymerase chain reaction – PCR – or Rapid Diagnostic Test that discriminate between currently infected agents, and its combination with a serology test like Neutralization Assay that is able to discriminate between immune and vulnerable healthy individuals, together with the role of enforcement to prevent interactions involving infected but asymptomatic agents. I find that isolating symptomatic individuals has a large effect at delaying and reducing the pick of infections. The combination of this policy with a PCR test is likely to represents only a negligible improvement in the absence of enforcement, whereas with full enforcement there is an additional delaying and reduction in the pick of infections. Social distancing alone cannot achieve similar effects without incurring in enormous output losses. I explore the combined effect of social distancing at early stages of the epidemic with a following period of tests and find that the best outcome is obtained with a light reduction of human interaction for about three months together with a subsequent test of the population over 40 days.