Entry/Congestion Game

Charles Holt

Public Goods

Experiment Software

This program sets up a multi-person game in which each person chooses whether or not to enter a market or other activity that can become congested by excess entry. The payoff for all people who enter is a decreasing function of the number of entrants, and the payoff for not entering is a constant. The incentives are typically such that each person would prefer to enter if the others are unlikely to do so, and would prefer to stay out if the others are likely to enter. If the number of participants is large, the equilibrium will be characterized by equal expected payoffs for entry and non-entry. Following a suggestion made by David Reiley, congestion effects can be controlled by imposing an entry fee that forces entrants to pay the external costs imposed on others. The entry fee or toll is set by the experimenter. Another setup option determines whether or not people can see the number of those in their group who have already entered at any given time, i.e. whether they can obtain a "traffic report."