MACROECONOMIC POLICY EVALUATION AND OPTIMAL CONTROL THEORY: A CRITICAL REVIEW OF SOME RECENT DEVELOPMENTS

Abstract. This survey addresses the recent literature on the application of optimal control theory and game theory to macroeconomic policy evaluation and design. This literature focuses on strategic interactions between governments and private agents engaged in dynamic non-cooperative games and emphasizes such issues as precommitment, credibility and reputation as important and endemic aspects of optimal policy design. A dominant theme is the problem of dynamic inconsistency and the inferiority of an equilibrium in single-stage full-information games without commitment. This may be alleviated in repeated games involving reputation effects and threat strategies designed to coerce rivals into pursuing particular strategies and to sustain a sequential equilibrium. The type and characteristics of a sequential equilibrium also depend importantly upon the information structure conditioning players’beliefs under uncertainty. Included here are separating and pooling equilibria, involving notions of learning, signalling and information revelation. Additional dimensions exist in stochastic systems which introduce other forms of uncertainty. Optimal control and game theory have also been applied to international macroeconomic policy design, with emphasis on the potential costs and benefits of non-cooperative and cooperative behaviour between countries and problems of international policy coordination.