title: Beyond Rational Decision-Making: Modelling the Influence of Cognitive Biases on the Dynamics of Vaccination Coverage.
abstract: BACKGROUND
  Theoretical studies predict that it is not possible to eradicate a disease under voluntary vaccination because of the emergence of non-vaccinating "free-riders" when vaccination coverage increases. A central tenet of this approach is that human behaviour follows an economic model of rational choice. Yet, empirical studies reveal that vaccination decisions do not necessarily maximize individual self-interest. Here we investigate the dynamics of vaccination coverage using an approach that dispenses with payoff maximization and assumes that risk perception results from the interaction between epidemiology and cognitive biases.
  
  
  METHODS
  We consider a behaviour-incidence model in which individuals perceive actual epidemiological risks as a function of their opinion of vaccination. As a result of confirmation bias, sceptical individuals (negative opinion) overestimate infection cost while pro-vaccines individuals (positive opinion) overestimate vaccination cost. We considered a feedback between individuals and their environment as individuals could change their opinion, and thus the way they perceive risks, as a function of both the epidemiology and the most common opinion in the population.
  
  
  RESULTS
  For all parameter values investigated, the infection is never eradicated under voluntary vaccination. For moderately contagious diseases, oscillations in vaccination coverage emerge because individuals process epidemiological information differently depending on their opinion. Conformism does not generate oscillations but slows down the cultural response to epidemiological change.
  
  
  CONCLUSIONS
  Failure to eradicate vaccine preventable disease emerges from the model because of cognitive biases that maintain heterogeneity in how people perceive risks. Thus, assumptions of economic rationality and payoff maximization are not mandatory for predicting commonly observed dynamics of vaccination coverage. This model shows that alternative notions of rationality, such as that of ecological rationality whereby individuals use simple cognitive heuristics, offer promising new avenues for modelling vaccination behaviour.
authors.affiliation: Université de Lille-Sciences et Technologies, UMR 8198 Evo-Eco-Paleo, Villeneuve d'Ascq, France.
authors.forename: Marina
authors.initials: M
authors.lastname: Voinson
authors.affiliation: Université de Lille-Sciences et Technologies, UMR 8198 Evo-Eco-Paleo, Villeneuve d'Ascq, France.
authors.forename: Sylvain
authors.initials: S
authors.lastname: Billiard
authors.affiliation: School of Anthropology and Museum Ethnography, University of Oxford, Oxford, United Kingdom.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Alvergne
mesh_terms: D003071:Cognition; D003141:Communicable Diseases / Q000453:epidemiology; D003657:Decision Making; D006801:Humans; D008954:Models, Biological; D014611:Vaccination