Strongly time-consistent solutions in cooperative dynamic games

Abstract

In the paper the evolution of dynamic game along the cooperative trajectory is investigated. Along cooperative trajectory at each time instant players find themselves in a new game which is a subgame of the originally defined game. In many cases the optimal solution of the initial game restricted to the subgame along cooperative trajectory fails to be optimal in the subgame. To overcome this difficulty we introduced (see Petrosyan and Danilov, Vestnik Leningrad Univ Mat Mekh Astronom 1:52–59, 1979; Petrosyan and Zaccour, J Econ Control 27(3):381–398, 2003; Yeung and Petrosyan, Subgame consistent economic optimization. Birkhauser, 2012) the special payment mechanism—imputation distribution procedure (IDP), or payment distribution procedure (PDP), but another serious question arises: under what conditions the initial optimal solution converted to any optimal solution in the subgame will remain optimal in the whole game. This condition we call strongly time-consistency condition of the optimal solution. If this condition is not satisfied players in reality may switch in some time instant from the previously selected optimal solution to any optimal solution in the subgame, and as result realize the solution which will be not optimal in the whole game. We propose different types of strongly time-consistent solutions for multicriterial control, cooperative differential, and cooperative dynamic games.