guest post by Jules Hedges
This is a post I’ve been putting off for a long time until I was sure I was ready. I am the “lead developer” of a thing called compositional game theory (CGT). It’s an approach to game theory based on category theory, but we are now at the point where you don’t need to know that anymore: it’s an approach to game theory that has certain specific benefits over the traditional approach.
I would like to start a conversation about “using my powers for good”. I am hoping particularly that it is possible to model microeconomic aspects of climate science. This seems to be a very small field and I’m not really hopeful that anyone on Azimuth will have the right background, but it’s worth a shot. The kind of thing I’m imagining (possibly completely wrongly) is to create models that will suggest when a technically-feasible solution is not socially feasible. Social dilemmas and tragedies of the commons are at the heart of the climate crisis, and modelling instances of them is in scope.
I have a software tool (https://github.com/jules-hedges/open-games-hs) that is designed to be an assistant for game-theoretic modelling. This I can’t emphasise enough: A human with expertise in game-theoretic modelling is the most important thing, CGT is merely an assistant. (Right now the tool also probably can’t be used without me being in the loop, but that’s not an inherent thing.)
To give an idea what sort of things CGT can do, my 2 current ongoing research collaborations are: (1) a social science project modelling examples of institution governance, and (2) a cryptoeconomics project modelling an attack against a protocol using bribes. On a technical level the best fit is for Bayesian games, which are finite-horizon, have common knowledge priors, and private knowledge with agents who do Bayesian updating.
A lot of the (believed) practical benefits of CGT come from the fact that the model is code (in a high level language designed specifically for expressing games) and thus the model can be structured according to existing wisdom for structuring code. Really stress-testing this claim is an ongoing research project. My tool does equilibrium-checking for all games (the technical term is “model checker”), and we’ve had some success doing other things by looping an equilibrium check over a parameter space. It makes no attempt to be an equilibrium solver, that is left for the human.
This is not me trying to push my pet project (I do that elsewhere) but me trying to find a niche where I can do some genuine good, even if small. If you are a microeconomist (or a social scientist who uses applied game theory) and share the goals of Azimuth, I would like to hear from you, even if it’s just for some discussion.