ABSTRACT
The billiard ball model turns out to be the starting point for the kinetic theory of gases.3 In a container full of many particles, all whizzing around and bumping into each other at all sorts of speeds, one property is always stable with respect to all the other elements. In the case of gases, that property is temperature. Certainly economic agents are more complicated than billiard balls. Nevertheless, the notions of interactive complexity and emergence are identical in both cases. Remember those music lovers at the El Farol bar. Aristotle may have been the first to recognize that the whole is something more than the sum of its parts. But it was the Scottish philosopher David Hume who impressed upon us the need to distinguish between the simple and the complex. As we showed in the example of movie selection, it’s also an important feature of products that we buy and sell in our everyday economic activities.
