We use daily data from Lombardy, the Italian region most affected by the COVID-19 outbreak, to calibrate a SIR model on each municipality. Municipalities with a higher initial number of cases feature a lower rate of diffusion, not attributable to herd immunity: there is a robust and strongly significant negative correlation between the estimated basic reproduction number (R0) and the initial outbreak size. This represents novel evidence of the prevalence-response elasticity in a cross-sectional setting, characterized by a same health system and homogeneous social distancing regulations. By ruling out alternative explanations, we conclude that a higher number of cases causes changes of behavior, such as a more strict adoption of social distancing measures among the population, that reduce the spread. This finding calls for the distribution of detailed epidemiological data to populations affected by COVID-19 outbreaks.

COVID-19: R0 is lower where outbreak is larger / P. Battiston, S. Gamba. - In: HEALTH POLICY. - ISSN 0168-8510. - 125:2(2021 Feb), pp. 141-147. [10.1016/j.healthpol.2020.10.017]

COVID-19: R0 is lower where outbreak is larger

S. Gamba
Ultimo
2021

Abstract

We use daily data from Lombardy, the Italian region most affected by the COVID-19 outbreak, to calibrate a SIR model on each municipality. Municipalities with a higher initial number of cases feature a lower rate of diffusion, not attributable to herd immunity: there is a robust and strongly significant negative correlation between the estimated basic reproduction number (R0) and the initial outbreak size. This represents novel evidence of the prevalence-response elasticity in a cross-sectional setting, characterized by a same health system and homogeneous social distancing regulations. By ruling out alternative explanations, we conclude that a higher number of cases causes changes of behavior, such as a more strict adoption of social distancing measures among the population, that reduce the spread. This finding calls for the distribution of detailed epidemiological data to populations affected by COVID-19 outbreaks.
Basic reproduction number; Containment; COVID-19; Prevalence-response elasticity; Social distancing
Settore SECS-P/01 - Economia Politica
Settore SECS-P/03 - Scienza delle Finanze
8-nov-2020
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2434/812362
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