The Theory of the Game of the British-Irish Border
What’s ostensibly most interesting about Neil McCulloch’s (early) analysis of Brexit and the British-Irish border is that a politically and philosophically charged situation is processed via a simple game theory argument into a prediction about negotiating side’s best strategy. McCulloch gives a game theory table in the article, justifies his choices for the numbers he gives in it, and proceeds to analyse its two Nash equilibria. He finds two: one in which both sides opt for a hard border, and one in which both sides opt for a soft border. McCulloch goes on to discuss how the situation will likely play out, noting that Ireland has a veto option over the deal and that the EU might attempt to use the border as a negotiating chip.
What’s particularly interesting is that the game theory table McCulloch gives is fundamentally different from one that would generate the Prisoner’s Dilemma, in that no option reflects a global utility maxima. At first it’s heartening to note that the two equilibria represent the two best outcomes, but it is then apparent that these equilibria cover both of the two possible outcomes; eventually, one side will give in to reach one of them.
This, however, raises the question of to what outcome the two (0, 0) cells—in which Ireland and Great Britain disagree as to what border they want—correspond. McCulloch doesn’t mention this. Clearly, a soft border will take agreement from both sides on a soft border, so it couldn’t be this. Naively, we might assume that the party advocating a hard border would simply make their side of the border hard, and that would be the end result. Alternatively, last-minute political shenanigans might make for something different altogether, perhaps a border of relaxed softness (there have been a variety of proposals over what might happen). I won’t comment on what the exact utilities of these options would be for both sides, but it does seem that they’d be inferior to an agreement due to the political and logistical hassle involved. However, as both parties will initially advocate for their preferred positions and not the best response to the position made by the other, it seems that it will take a while (yet, it’s 2019 now) for the game theory to start to play out.