Game Theory in the context of Epidemics
One of the fundamental assumptions of game theory is that each player is rational or is a “rational decision maker” (RDM). Generally this means that each player is looking to maximize their payoff in a given game. We have exclusively been looking at games with complete information: each player knows the exact expected payoff of any given strategy profile. Consequently each player is aware of their dominant strategies. For instance, in the Prisoner’s Dilemma, each player’s dominant strategy is to confess: either you go free or you spend four years imprisoned, an improvement to either spending a single year or ten if your partner confesses.
Most situations in aren’t as clean. Consider the game of poker: while you can calculate the odds of winning, your opponent is playing with information you do not have, and vice versa. This schema might be closer to modeling disease outbreaks or epidemics. While one could perceive reactions to a disease as being irrational (such as refusing a vaccine, or staying in physical contact with the infected) it is more based off of a rational player’s lack of information. We’ll refer to the game played during a disease outbreak as the Epidemic Game for this post.
An important facet of this game, as discussed in the attached article, by Poletti et al, is the payoff for each player changes based on how they view the threat of a given disease; each player has incomplete information over the severity of the outbreak. For instance, in the case of the H1N1 outbreak the initial public reaction was rational with players “taking precautions and behaving responsibly.” This makes sense given that players had a perception of H1N1 being a global disaster in the making. Poletti et al compare this to the initial reaction to Ebola which was a lot more mild due to a lack of information. They found that when players perceive a given disease as being threatening, they take rational steps to avoid contracting the disease: limit contact with potentially infected persons, get vaccinated if possible, etc. On the other hand, if their perception is that of low-risk, regardless of the reality, they will take irrational actions such as refusing vaccines.
Their final conclusion is that it is on policymakers and the media to reliably inform the people about potential outbreaks. By reducing the amount of incomplete information in the game, this makes dominant strategies for a given outbreak more clear.
Link: Using game theory to predict people’s behavior in an epidemic