Nyarko, Y. (2010). Most Games Violate the Common Priors Doctrine. International Journal of Economic Theory, 6(1), 189-194.
The type of a player in a game describes the beliefs of that player about the types of others.
Nyarko, Y. (1998). Bayesian Learning and Convergence to Nash Equilibria without Common Priors. Economic Theory, 11(3), 643-655.
Consider an infinitely repeated game where each player is characterized by a ‘type’ which may be unknown to the other plays in the game. Suppose further that each player’s belief about others is independent of that player’s type…
Nyarko, Y. (1997). Convergence in Economic Models with Bayesian Hierarchies of Beliefs. Journal of Economic Theory, 74(2), 266-296.
I study a model where hierarchies of beliefs (the beliefs about the beliefs of other agents, etc.) are important. I provide conditions under which optimal actions of agents will converge to the Nash equilibrium of the model characterized by the true, previously unknown ``fundamentals.''
Kiefer, N., & Nyarko, Y. “Savage-Bayesian Models of Economics.” Essays in learning and rationality in economics and games, Basil Blackwell, 40-62, 1995.
The “state of the art” in learning models in economics is highly unsettled. On the one hand, we have the optimizing models in which learning occurs as a byproduct…
Nyarko, Y. (1994). On the Convexity of the Value Function in Bayesian Optimal Control Problems. Economic Theory, 4(2), 303-309.
I study the question on the convexity of the value function and Blackwell (1951)’s Theorem and relate this to the uniqueness of optimal policies…
Nyarko, Y., Woodford, M., & Yannelis, N. C. (1994). Bounded Rationality and Learning. Economic Theory, 4(6), 811-820.
Many have objected to the use of the Nash equilibrium (or more generally, Bayesian Nash equilibrium) concept in game theory, and similarly to the use of the rational expectations concept in the theory of competitive markets…
Nyarko, Y. (1994). Bayesian Learning Leads to Correlated Equilibria in Normal Form Games. Economic Theory, 4(6), 821-841.
Consider an infinitely repeated normal form game where each player is characterized by a “type” which may be unknown to the other players of the game…
Nyarko, Y. (1991). On the Convergence of Bayesian Posterior Processes in Linear Economic Models, Counting Equations and Unknowns. Journal of Economic Dynamics and Control, 15(4), 687-713.
I propose a technique, counting ‘equations’ and ‘unknowns’, for determining when the posterior distributions of the parameters of a linear regression process converge to their true values.
Nyarko, Y. (1991). Learning in Mis-Specified Models and the Possibility of Cycles. Journal of Economic Theory, 55(2), 416-427.
I study the problem of a monopolist maximizing a sum of discounted profits facing a linear demand curve whose slope and intercept are unknown. I show that if the monopolist has a mis-specified model…
Kiefer, N., & Nyarko, Y. “Optimal Bayesian Control of a Nonlinear Regression Process with Unknown Parameters.” Modeling and Control of Systems, Lecture Notes in Control and Information Sciences, edited by Austin Blaquiére, Springer, Berlin, Heidelberg, 355-362, 1989.
Economic Agents operating in uncertain, stochastic environments can face a tradeoff between current period expected reward and accumulation of information of uncertain value.
Kiefer, N., & Nyarko, Y. (1989). Optimal Control of an Unknown Linear Process with Learning. International Economic Review, 30(3), 571-586.
Optimal control of a linear process with unknown parameters is considered when the horizon is infinite and rewards are discounted. Active learning strategies are considered…
Kiefer, N., & Nyarko, Y. “Control of a Linear Regression Process with Unknown Parameters.” Dynamic Econometric Modelling, edited by Barnett et al., Cambridge University Press, 105-120, 1988.
Applications of forms of control theory to economic policy making have been studied by Theil (1958), Chow (1975, 1981), and Prescott (1972). Many of the applications are approximations to the optimal policy…