This paper formalizes the idea that more hedging instruments may destabilize markets when traders are heterogeneous and adapt their behavior according to experience based reinforcement learning. We investigate three different economic settings, a simple mean-variance asset pricing model, a...

We study participation games with negative feedback, i.e. games where players choose either to participate in a certain project or not and where the payoff for participating decreases in the number of participating players. We use the replicator dynamics to model the competition between...

We introduce a framework to analyze the interaction of boundedly rational heterogeneous agents repeatedly playing a participation game with negative feedback. We assume that agents use different behavioral rules prescribing how to play the game conditionally on the outcome of previous rounds. We...

We empirically evaluate a behavioural model with boundedly rational traders who disagree about the persistence of deviations from the fundamental stock price. Fundamentalist traders believe in mean-reversion, while chartists extrapolate trends. Agents gradually switch between the two rules,...

Expectations play a crucial role in modern macroeconomic models. We replace the common assumption of rational expectations in a New Keynesian framework by the assumption that expectations are formed according to a heuristics switching model that has performed well in earlier work. We show how...

This experiment compares the price dynamics and bubble formation in an asset market with a price adjustment rule in three treatments where subjects (1) submit a price forecast only, (2) choose quantity to buy/sell and (3) perform both tasks. We find deviation of the market price from the...

We investigate expectation formation in a controlled experimental en-vironment. Subjects are asked to predict the price in a standard asset pricingmodel. They do not have knowledge of the underlying market equilibrium equa-tions, but they know all past realized prices and their own predictions....

A large set of 5350 trend following technica! trading rules is applied to LIFFEand CSCE cocoa futures prices, and tothe Pound-Dollar exchange rate, in the period 1983:1-1997:6. We find that 72% ofthe trading rules generatespositive profits, even when correcting for transaction and borrowing...

A simple asset pricing model with two types of adaptively learning traders,fundamentalists and technical analysts, is studied. Fractions of these tradertypes, which are both boundedly rational, change over time according toevolutionary learning, with technical analysts conditioning their...

These notes review two simple heterogeneous agent models in economics and finance. The first is a cobweb model with rational versus naive agents introduced in Brock and Hommes (1997). The second is an asset pricing model with fundamentalists versus technical traders introduced in Brock and...