Game Theory in the Philosophy of Convention
Certain concepts, for instance money, result from convention. It is through convention alone that a piece of paper is considered as valuable as important goods and services. The concept of convention is invoked here to say that some things result from agreement that is up to us, “undetermined by human nature or by intrinsic features of the non-human world”. Convention becomes an intriguing philosophical topic when we ask if things like morality, language, mathematics, logic, etc. are also results of convention. Because of this, the nature of convention itself becomes subject to philosophical investigation.
When it comes to the question of why people adhere to conventions at all, the influential philosopher David Hume comments that this is due to each participant’s belief that other participants obey the convention. Given this belief, each participant has a reason to obey the conventions himself. A more recent philosopher, David Lewis, developed this theory of convention much further through the use of game theory. Lewis characterizes convention as “an arbitrary, self-perpetuating solution to a recurring coordination problem.”
Let’s break down this dense description. Consider two people A and B performing some action. A coordination problem is what arises due to the existence of multiple ways for these people to perform their actions, of which perhaps some lead to a mutually desirable result. For instance, two cars driving towards each other on a highway have multiple ways they could do so. Both can drive on the same side, whether it be the left or right side, in which case they will end up in collision. On the other hand, one could drive on the left lane while the other drives on the right side, or vice versa. This is the best outcome as it avoids collision. In order to achieve mutually desirable result (that is, to avoid collision), these drivers have to coordinate. As it happens frequently in daily life, such a phenomena can be described as a recurring coordination problem. As Lewis suggests, convention is a way of solving this problem. Convention is arbitrary in the sense that instead of the existing rules to drive on a particular lane, the rules could easily have been that the other lane is the preferable one. Convention Is also a self-perpetuating solution in that “no one has the reason to deviate from it given that others conform.” In this example, if everyone else always drives on the right side, I have no reason not to do as well, since otherwise I will end up in collision.
Such strategies that lead to desirable results for both parties are described by Nash equilibrium. In his original paper, Lewis actually pushes this further to ultimately reach a notable conclusion that can be summarized as follows: “everyone prefers that everyone else conform if at least all but one conform.” Just like most philosophical topics, philosophers are far from reaching a consensus on various aspects of convention. However, it is clear that Lewis’ work in formalizing what seemed like an obvious and intuitive theory of Hume’s through game theory was a significant leap forward.
Quoted article: https://plato.stanford.edu/entries/convention/