I am teaching a new PhD course this year called “Conflict and Cooperation”. The title is broad enough to include almost anything I want to teach.  This is an advantage – total freedom! – but also a problem – what should I teach?  The course is meant to be about environments with weak property rights where one player can achieve surplus by stealing it and not creating it.  To give some structure, I have adopted Hobbes’s theories of conflict to give structure to the lectures.  Hobbes says the three sources of conflict are greed, fear and honour. The solution is to have a government or Leviathan which enforces property rights.

Perhaps reputation models à la Kreps-Milgrom-Roberts-Wilson come closest to offering a game theoretic analysis of honour (e.g. altruism in the finitely repeated prisoner’s dilemma). But I will only do these if I get the time as this material is taught in many courses.  So, I decided to begin with greed.

I started with the classic guns vs butter dilemma: why produce butter when you can produce guns and steal someone else’s butter?  This incentive leads to two kinds of inefficiency: (1) guns are not directly productive and (2) surplus is destroyed in war waged with guns.  The second inefficiency might be eliminated via transfers (the Coase Theorem in this setting). This still leaves the first inefficiency which is similar to the underinvestment result in hold-up models in the style of Grossman-Hart-Moore.  With incomplete information, there can be inefficient war as well.  A weak country has the incentive to pretend to be tough to extract surplus from another.  If its bluff is called, there is a costly war. (Next time, I will move this material to a later lecture on asymmetric information and conflict as it does not really fit here.)

These models have bilateral conflict. If there are many players, there is room for coalitions to form, pool guns, and beat up weaker players and steal their wealth. What are stable distributions of wealth? Do they involve a dictator and/or a few superpowers? Are more equitable distributions feasible in this environment? It turns out the answer is “yes” if players are “far-sighted”. If I help a coalition beat up some other players, maybe  my former coalition-mates will turn on me next. Knowing this, I should just refuse to join them in their initial foray. This can make equitable distributions of wealth stable.

I am writing up notes and slides as I am writing a book on this topic with Tomas Sjöström.  Here are some slides.