An occasional series on the practice of formal theory — not what the models say about the world, but what it’s actually like to build them. How do you choose between equilibrium concepts? What do you do with a result you don’t believe? Why does robustness feel like a moving target? For readers who want to see behind the curtain.
I’ve joked before with people that I liken social science models to rock songs. My actual mapping is horribly incomplete. So I’ll set that chatter to the side. That said, the practice of modeling, in my experience, is a lot like rock ‘n roll. You give me a topic, and I’ll think for a minute, … Read more
I just finished writing this meandering post about sequential rationality. Subsequently, I thought of these better examples that come from different angles. First, a classic example (mostly) of failures of sequential rationality: food challenges. In most cases, most people who think they can eat that amount of food can eat that amount of food. They just end … Read more
It’s a new year, the ground is covered with more-than-ankle-deep snow, and I told a friend tonight that it seems like, over the past couple of weeks, the notion of a “day of the week” has lost all meaning. This is how winter break winds to a quiet close. It is an opportunity to take … Read more
I am a game theorist. I love thinking about situations as strategic interactions. As a game theorist, I make assumptions all the time. (And I assume you do, too, in whatever you do. THAT’S META.) In political science, there are, broadly defined and in my estimation, four categories of theory. Game theory (which includes mechanism … Read more
Most of my research starts with the presumption that individuals are rational. By this, I mean that they know the rules of the game, and they also know that the other players are rational.[1] Simple empirical observation indicates the inherent contestability of this presumption. So, why do I continue to adopt it? Well, I have … Read more
As a theorist, I write models. (There is a distinction between “types” of theorists in political science. It is casually and superficially descriptive: all theorists write models, just in different languages.) One of the biggest complaints I hear—from both (some) fellow theorists and (at least self-described) “non-theorists”—is the following equivalent complaint in different terms: Theorists: …but, … Read more
[This is an installment in my irregular series of articles on the minutiae of what I do, “Inside Baseball.”] Lately I have been working on a couple of models with various signaling aspects. It has led me to think a lot more about both “testing models” and common knowledge of beliefs. Specifically, a central question … Read more
Note: This is the first of what might be an irregular “column” of sorts, “Inside Baseball,” focusing on the minutiae of my research, as opposed to current events. The heart of game theory is “what would everyone else think if I do what I am about to do differently?” This is slightly different than … Read more