Shostack + Friends Blog Archive


Nobody goes there anymore, it's too crowded

In 1994, Brian Arthur introduced the `El Farol Bar’ problem as a paradigm of complex economic systems. In this model a population of agents have to decide whether to go to the bar each thursday night. All agents like to go to the bar unless it is too crowded (i.e. when more that 60% of the agents go). So in order to epitomise its own utility each agent has to try and predict what everybody else will do. The problem is set up so that any model of the problem that is shared by most of the agents is self-defeating. For if most agents predict that the bar will not be too crowded then they will all go and it will be too crowded, and vice versa.

Neat! From a paper by Bruce Edmonds. See also Arthur’s page on the subject. Of course, Yogi Bera was discussing a slightly different problem.

One comment on "Nobody goes there anymore, it's too crowded"

  • Josh Rubin says:

    The agents should have read Kant. They should choose
    an action that, when universally followed, does not
    lead to unstable/paradoxical/undesired behavior.
    (Actually, Kant would leave out “undesired”, since
    he believed consequences have nothing to do with what is right.)
    In this case, they should choose a probability between 0 and 1 of going to the bar, and go with
    that probability. They can adjust the probability based on experience.
    I think Utilitarians would do the same.

Comments are closed.