Traditional finance is built on the rationality paradigm. This chapter discusses simple models from an alternative approach in which financial markets are viewed as complex evolutionary systems. Agents are boundedly rational and base their investment decisions upon market forecasting heuristics....

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,...

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....

This paper surveys work on dynamic heterogeneous agent models (HAMs) in economics and finance. Emphasis is given to simple models that, at least to some extent, are tractable by analytic methods in combination with computational tools. Most of these models are behavioral models with boundedly...

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...

We estimate a dynamic asset pricing model characterized by heterogeneous boundedly rational agents. The fundamental value of the risky asset is publicly available to all agents, but they have different beliefs about the persistence of deviations of stock prices from the fundamental benchmark. An...