Game Theory and Covid-19 Vaccines!
By: Julia Beitel
Researcher couple Madhur Anand and Chris Bauch were passing time during lockdown in 2020, when they decided to take a closer look at the pandemic’s human behavioral patterns with game theory. It became clear, after analyzing the pandemic’s dynamics, that the vaccine debate was a so-called “prisoner’s dilemma game.” Deciding to get (or not get the vaccine) relied on a number of factors, but group cooperation and responsibility were at the upmost importance for societal wellbeing. Additionally, they realized they could model human population behavior with simple models of game theory. It is clear that game theory and the ways which covid vaccines save lives are deeply connected.
Matrix of protection (direct vs. indirect) by covid vaccine:
| Vaccine (others) | No Vaccine (others) | |
|---|---|---|
| Vaccine (you) | Direct, direct.
(Everyone protected!) |
Direct, in-direct (free-ride).
(Some protected.) |
| No Vaccine (you) | In-direct (free-ride), direct.
(Some protected.) |
None, none.
(No one protected!) |
I thought we should take a look one step deeper by visualizing the indirect and direct protection from vaccines as a matrix of game theory to see how the patterns of society’s decisions impact others’ health and wellbeing. If we take a look at the matrix below, we can see that when you are vaccinated and others are vaccinated, you are both directly protected from Covid-19. Next, when you do not get vaccinated, but others do, you are free-riding off of their vaccination. Furthermore, you are receiving the benefits of their lowered transmission rates even thought you are unvaccinated. This causes you to be indirectly benefitted by the vaccine that others have received and they are directly benefiting from being vaccinated, but are still at risk of exposure because you are not fully protected. Third, if you are vaccinated but others are not, we can see the reciprocal of the last example: You are directly protected from the vaccine, but others are free-riding on your vaccinated protection and following lowered transmission rates. You are still not fully protected because the others who did not get vaccinated can still get you sick from being infected themselves. Lastly, if you are unvaccinated and others are unvaccinated, no one is protected and everyone is at risk for being infected by the vaccine.
This matrix goes to show how the largest incentive of them all is indecision and selfishness by free-riding, as the only other incentive to get the vaccine is altruism, or one’s moral responsibility to society. While the vaccine debate has turned political in the last few years, it is clear that with the more people that get vaccinated, the more people we can protect. Modeling this behavior with game theory helps to show the direct vs. indirect protection by the covid vaccine, ideally giving those who object to the vaccine more clarity on its societal benefits.
Article link=> https://www.nytimes.com/2020/12/20/health/virus-vaccine-game-theory.html