This discussion paper resulted in a publication in the 'SIAM Journal on Optimization', 2006, 16, 854-870. <P> It is well known that an upper semi-continuous compact- and convex-valued mapping fi from a nonempty compact and convex set X to the Euclidean space of which X is a subset has at least one...</p>

To isolate the impact of the assumption of model-consistent expectations, this paper proposes a baseline case in which households are individually rational, have full information and learn using forecast rules specified as in the minimum state variable representation of the economy. Applying...

This paper analyses a two-player game of strategic experimentation with two-armed bandits.At least one of the arms is risky in the sense that it may not yield a lumpsum payoff. There is payoff externality between the players and they differ in their ability to learn across the risky arm. Either...

In this paper, I examine the effect of introducing heterogeneity between players in a model of strategic experimentation. I consider a two-armed bandit problem in continuous time with one safe arm and a risky arm. There are two players and each has an access to such a bandit. A player using the...

This paper considers a two-armed bandit problem with one safe arm and one risky arm. The risky arm if good, can potentially experience two kinds of arrivals. One is publicly observable and the other is private to the agent who experiences it. The safe arm experiences publicly observable arrivals...

This paper considers a version of Bush and Mosteller's stochastic learning theory in the context of games. We compare this model of learning to a model of biological evolution. The purpose is to investigate analogies between learning and evolution. We and that in the continuous time limit the...

This risk.paper considers a simple learning process for decision problems under All behaviour change derives from the reinforcing or deterring effect of instantaneous payoff experiences. Payoff experiences are reinforcing or deterring depending on whether the payoff exceeds an aspiration level...

Fictitious play and "gradient" learning are examined in the context of a large population where agents are repeatedly randomly matched. We show that the aggregation of this learning behaviour can be qualitatively di®erent from learning at the level of the individual. This aggregate dynamic...

The problem of fair pricing of contingent claims is well understood in the contex of an arbitrage free, complete financial market, with perfect information : the so-called arbitrage approach permits to construct a unique valuation operator compatible with observed price rocesses. In the more...

We consider a complete financial market with primitive assets and derivatives on these primitive assets. Nevertheless, the derivative assets are non-redundant in the market, in the sense that the market is complete, only with their existence. In such a framework, we derive an equilibrium...