Game Theory and the Spread of Disease
This article provides an interesting perspective on the spread of disease through the lens of game theory. The analysis is predicated on the basic game theoretic idea that individuals will generally do whatever action yields them the greatest benefit. In many scenarios this is good; people’s interests align with those of society (i.e. starting a business provides individual gain and contributes to the economy) and so their personal actions benefit both themselves and society. However, in other cases, such as the one this article describes, individuals’ interests go against what would be best for society and problems can arise.
The article argues that disease outbreaks can be caused/contributed to by this idea of individuals acting in a self-interested manner. I’ll describe this idea in the context of people choosing whether or not to vaccinate in order to make the discussion more concrete. This situation can be modeled loosely by a game with a player for every individual in society. So long as most individuals choose to vaccinate, all individuals (i.e. society) receive a reward in the fact that no one becomes infected by a given disease. However, vaccinating individuals must go through the inconvenience/monetary cost/perceived risk (for people who are anti-vaccination) of the vaccine and so additionally receive a slightly negative reward in that sense. Naturally, then, there will be certain players who opt to forgo a vaccination in order to avoid this penalty. This is generally fine; as long as most people vaccinate, the chance of a significant outbreak in society is low. However, if enough people do not vaccinate, the chance of an outbreak increases and can lead to scenarios like the one we saw with measles and mumps.
These situations can be thought of as complex variations on the classic Prisoner’s Dilemma game. It is in each player’s best interest not to vaccinate (save the cost, etc.), but everyone loses if enough people take this option.
The connection between this article and our course is clear; viewing the scenario in terms of game theory helps to provide a rational explanation for what otherwise seems to be suboptimal behavior. (everyone benefits from getting a vaccine) As I described above, the tools of game theory (rewards and choosing what maximizes them) make for an informative analysis of the situation. Further, I believe (and the article suggests) that viewing things like vaccination from this perspective can provide hints on how to mitigate bad outcomes in terms of the spread of disease. Governments and officials should attempt to provide incentives which help to align the interests of people with the interest of society. If they could make getting a vaccine a dominant strategy for example, people would all vaccinate of their own accord and avoid negative outcomes for everyone. Concretely, this could be achieved by taxation or better education surrounding vaccines/infectious disease to raise the perceived risk of infection significantly. In game theory terms, aligning the interests of everyone would lead to equilibria in which society achieves the highest possible reward (no disease outbreaks).
Article: https://phys.org/news/2018-09-game-theory-disease-outbreaks.html