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Homophily and Infections: Static and Dynamic Effects




We analyze the effect of homophily in an epidemics between two groups of agents that differ in vaccination rates (“vaxxers" and “anti-vaxxers"). The steady state infection rate is hump-shaped in homophily, whereas the cumulative number of agents infected during an outbreak is u-shaped. If vaccination rates are endogenous, homophily has the opposite impact on the two groups, but the qualitative behavior of the aggregate is unchanged. However, the sign of the group-level impact is the opposite if vaccination is motivated by infection risk or by peer pressure. If motivations are group-specific, homophily can be harmful for both groups.

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  • Matteo Bizzarri & Fabrizio Panebianco & Paolo Pin, 2023. "Homophily and Infections: Static and Dynamic Effects," CSEF Working Papers 672, Centre for Studies in Economics and Finance (CSEF), University of Naples, Italy.
  • Handle: RePEc:sef:csefwp:672

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    References listed on IDEAS

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    Cited by:

    1. Josselin Thuilliez & Nouhoum Touré, 2024. "Opinions and vaccination during an epidemic," Post-Print hal-04490900, HAL.
    2. Josselin Thuilliez & Nouhoum Touré, 2024. "Opinions and vaccination during an epidemic," Université Paris1 Panthéon-Sorbonne (Post-Print and Working Papers) hal-04490900, HAL.

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    More about this item


    Homophily; seasonal diseases; vaccination; anti-vaccination movements; SIS-type model.;
    All these keywords.

    JEL classification:

    • D62 - Microeconomics - - Welfare Economics - - - Externalities
    • D85 - Microeconomics - - Information, Knowledge, and Uncertainty - - - Network Formation
    • I12 - Health, Education, and Welfare - - Health - - - Health Behavior
    • I18 - Health, Education, and Welfare - - Health - - - Government Policy; Regulation; Public Health

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    This paper has been announced in the following NEP Reports:


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