Stationary Markov perfect equilibria in discounted stochastic games

The existence of stationary Markov perfect equilibria in stochastic games is shown under a general condition called “(decomposable) coarser transition kernels”. This result covers various earlier existence results on correlated equilibria, noisy stochastic games, stochastic games with finite actions and stateindependent transitions, and stochastic games with mixtures of constant transition kernels as special cases. A remarkably simple proof is provided via establishing a new connection between stochastic games and conditional expectations of correspondences. New applications of stochastic games are presented as illustrative examples, including stochastic games with endogenous shocks and a stochastic dynamic oligopoly model.