Subgame-Perfection in Quitting Games with Perfect Information and Differential Equations
Eilon Solan
Managerial Economics and Decision Science Department, Kellogg School of Management, Northwestern University, and School of Mathematical Sciences, Tel Aviv University, 69978 Tel Aviv, Israel
eilons{at}post.tau.ac.il
We introduce a new approach to studying subgame-perfect equilibrium payoffs in stochastic games: the differential equations approach. We apply our approach to quitting games with perfect information. Those are sequential games in which at every stage one of n players is chosen; each player is chosen with probability 1/n. The chosen player i decides whether to quit, in which case the game terminates and the terminal payoff is some vector ai
Rn, or whether to continue, in which case the game continues to the next stage. If no player ever quits, the payoff is some vector a*
Rn. We define a certain differential inclusion, prove that it has at least one solution, and prove that every vector on a solution of this differential inclusion is a subgame-perfect equilibrium payoff.
Key Words: stochastic games; Dynkin games; subgame-perfect equilibrium; differential inclusions; quitting games
History: Received: September 17, 2002;
revision received: March 3, 2004;
Copyright © 2005 by INFORMS.