Economic Theory ( IF 1.423 ) Pub Date : 2021-07-14 , DOI: 10.1007/s00199-021-01377-2 Miltiadis Makris 1
Motivated by the Covid-19 epidemic, we build a SIR model with private decisions on social distancing and population heterogeneity in terms of infection-induced fatality rates, and calibrate it to UK data to understand the quantitative importance of these assumptions. Compared to our model, the calibrated benchmark version with constant mean contact rate significantly over-predicts the mean contact rate, the death toll, herd immunity and prevalence peak. Instead, the calibrated counterfactual version with endogenous social distancing but no heterogeneity massively under-predicts these statistics. We use our calibrated model to understand how the impact of mitigating policies on the epidemic may depend on the responses these policies induce across the various population segments. We find that policies that shut down some of the essential sectors have a stronger impact on the death toll than on infections and herd immunity compared to policies that shut down non-essential sectors. Furthermore, there might not be an after-wave after policies that shut down some of the essential sectors are lifted. Restrictions on social distancing can generate welfare gains relative to the case of no intervention. Milder but longer restrictions on less essential activities might be better in terms of these welfare gains than stricter but shorter restrictions, whereas the opposite might be the case for restrictions on more essential activities. Finally, shutting down some of the more essential sectors might generate larger welfare gains than shutting down the less essential sectors.
中文翻译:
Covid 和与异质人口的社会疏远
在 Covid-19 流行病的推动下,我们建立了一个 SIR 模型,该模型在感染引起的死亡率方面对社会疏远和人口异质性进行了私人决策,并将其校准到英国数据以了解这些假设的定量重要性。与我们的模型相比,具有恒定平均接触率的校准基准版本显着高估了平均接触率、死亡人数、群体免疫力和流行率峰值。相反,具有内生社会距离但没有异质性的校准反事实版本严重低估了这些统计数据。我们使用我们的校准模型来了解缓解政策对流行病的影响如何取决于这些政策在各个方面引起的反应人口细分。我们发现,与关闭非必要部门的政策相比,关闭一些必要部门的政策对死亡人数的影响比对感染和群体免疫的影响更大。此外,在关闭一些重要行业的政策取消后,可能不会出现后浪。相对于不干预的情况,对社会疏远的限制可以产生福利收益。就这些福利收益而言,对不太重要的活动进行更温和但更长时间的限制可能比更严格但更短的限制更好,而对更重要活动的限制可能正好相反。最后,关闭一些更重要的部门可能比关闭不太重要的部门产生更大的福利收益。