{"title":"Susceptible-infected-recovered model with stochastic transmission","authors":"Christian Gouriéroux, Yang Lu","doi":"10.1002/cjs.11835","DOIUrl":null,"url":null,"abstract":"<p>The susceptible-infected-recovered (SIR) model is the cornerstone of epidemiological models. However, this specification depends on two parameters only, which results in its lack of flexibility and explains its difficulty to replicate the volatile reproduction numbers observed in practice. We extend the standard SIR model to a semiparametric SIR model, by first introducing a functional parameter of transmission, and then making this function stochastic. This leads to a SIR model with stochastic transmission. Our model is particularly tractable. We derive its closed-form solution and use it to compute key indicators, such as the condition (and the threshold) of herd immunity and the timing of the peak. When the population size is finite and the observations are in discrete time, there is also observational uncertainty. We propose a nonlinear state-space framework under which we analyze the relative magnitudes of the observational and intrinsic uncertainties during the evolution of the epidemic. We emphasize the lack of robustness of the notion of herd immunity when the SIR model is time-discretized.</p>","PeriodicalId":55281,"journal":{"name":"Canadian Journal of Statistics-Revue Canadienne De Statistique","volume":"53 2","pages":""},"PeriodicalIF":0.8000,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/cjs.11835","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Canadian Journal of Statistics-Revue Canadienne De Statistique","FirstCategoryId":"100","ListUrlMain":"https://onlinelibrary.wiley.com/doi/10.1002/cjs.11835","RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"STATISTICS & PROBABILITY","Score":null,"Total":0}
引用次数: 0
Abstract
The susceptible-infected-recovered (SIR) model is the cornerstone of epidemiological models. However, this specification depends on two parameters only, which results in its lack of flexibility and explains its difficulty to replicate the volatile reproduction numbers observed in practice. We extend the standard SIR model to a semiparametric SIR model, by first introducing a functional parameter of transmission, and then making this function stochastic. This leads to a SIR model with stochastic transmission. Our model is particularly tractable. We derive its closed-form solution and use it to compute key indicators, such as the condition (and the threshold) of herd immunity and the timing of the peak. When the population size is finite and the observations are in discrete time, there is also observational uncertainty. We propose a nonlinear state-space framework under which we analyze the relative magnitudes of the observational and intrinsic uncertainties during the evolution of the epidemic. We emphasize the lack of robustness of the notion of herd immunity when the SIR model is time-discretized.
期刊介绍:
The Canadian Journal of Statistics is the official journal of the Statistical Society of Canada. It has a reputation internationally as an excellent journal. The editorial board is comprised of statistical scientists with applied, computational, methodological, theoretical and probabilistic interests. Their role is to ensure that the journal continues to provide an international forum for the discipline of Statistics.
The journal seeks papers making broad points of interest to many readers, whereas papers making important points of more specific interest are better placed in more specialized journals. The levels of innovation and impact are key in the evaluation of submitted manuscripts.