Estimated reproduction ratios in the SIR model

Abstract

The aim of this article is to understand the extreme variability in estimates of the reproduction ratio R0 observed in practice. For expository purposes, we consider a discrete-time, stochastic version of the susceptible-infected-recovered model and introduce different approximate maximum likelihood estimators of R0. We carefully discuss the properties of these estimators and illustrate, by a Monte Carlo study, the widths of confidence intervals for R0.