Covid-19 Vaccination Payoff is a Prisoner’s Dilemma
Article: https://www.nytimes.com/2020/12/20/health/virus-vaccine-game-theory.html
Two researchers, Madhur Anand and Chris Bauch decided to model vaccine rollout using game theory to see in which way releasing vaccines could minimize the spread of Covid-19. By modeling the spread of Covid-19 through game theory, the researchers remarked how this was essentially a more complex version of “Prisoner’s Dilemma,” the first type of game theory model we discussed in class. While there was no option to confess or not confess, “players” (people in society) had to either cooperate and get vaccinated or choose not to, where their decisions had a payoff for the common good and individuals.
This game theory application is quite complex in the fact that each individual action had its own tradeoff, not just one overarching choice to confess or not confess. People in society had to choose to wash their hands, wear masks, socially distance, etc. at the cost of being annoyed and isolated. Not only that, but people had to decide if they would immediately get the vaccine, wait and see what the side effects were, or just not get vaccinated and benefit from the overall lower transmission rates due to everyone else getting vaccinated (a free ride). Dr. Bauch described this as a prisoner’s dilemma because people felt less at risk when infection levels were low, creating an endless cycle of ebbing transmission rates.
Another interesting aspect of applying Game Theory to Covid-19 that was brought up was the fact that there was a sharp distinction between vaccination for self-interest and the common good. While people maximizing self-interest (individual payoff) is a Nash equilibrium, as we discussed in class, sometimes a Nash equilibrium is not necessarily the most socially optimal. In this case, research by a doctor including psychological data revealed that if individuals made vaccination decisions based on altruism, the overall payoff was beyond Nash equilibrium and served the common good even better.
What this research revealed most importantly was that because game theory included human behavior into its modeling, it was more accurate than other infectious disease models that failed to account for the flux in human behavior. While using game theory to model the spread of infectious diseases is uncommon, clearly it can prove more accurate as in this case.
In class, we used the Prisoner’s Dilemma as an introduction to Game Theory due to its simplicity. Here we see that when you repeatedly consider a prisoner’s dilemma in multiple scenarios, it can accurately represent something as current and important as the spread of Covid-19 and vaccination distribution. Mathematicians often just like to look at numbers and model them to make informed decisions. With game theory, as we see here, the incorporation of human behavior as a fluctuation factor rather than a fixed constant was crucial in improving the accuracy of these researchers’ models. As a result, we can see how Game Theory is relevant outside of just games and war, but to issues that are pressing in modern day.