This book, originally published in 1990, deals with the stabilisation and control of an economic system in a dynamic setting. Unlike studies which consider only the case of centralised policy-making, Professor Petit examines both the situation in which policy decisions are taken by a single policy-maker and the case of group policy-making. The wide-ranging economic implications of the use of these methods are thoroughly discussed. The tools of optimal control and differential game theory, and their advantages and drawbacks, are examined, along with methodological implications of introducing expectations into the policy problem. This lucid and comprehensive study of control theory and dynamic games will be of great use both to economists interested in learning mathematical methods and to mathematicians interested in their economic applications.