GAME TEHORY IS THE STUDY OF MULTIPERSON DECISION PROBLEMS. SUCH PROBLEMS ARISE FREQUENTLY IN ECONOMICS. AS IS WIDELY APPRECIATED, FOR EXAMPLE, OLIGOPILIES PRESENT ULTIPERSON PROBLEMS EACH FIRM MUST CONSIDER WHAT THE OTHERS WILL DO. BUT MANY OTHER THAN INDUSTRIAL ORGANIZATION. AT THE MICRO LEVEL, MODELS OF TRADING PROCESSES (SUCH AS BARGAINING AND AUCTION MODELS) INVOLVE GAME THEORY.