Price stability and volatility in markets with positive and negative expectations feedback: an experimental investigation

The evolution of many economic variables is affected by expectations that economic agents have with respect to the future development of these variables. Here we show, by means of laboratory experiments, that market behavior depends to a large extent on how the realized market price responds to an increase in average price expectations. If it responds by decreasing, as in commodity markets, prices converge quickly to their equilibrium value, confirming the rational expectations hypothesis. If the realized price increases after an increase of average expectations, as is typical for financial markets, large fluctuations in realized prices are likely

More hedging instruments may destabilize markets

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 general equilibrium two-period overlapping generations model with heterogeneous expectations and a noisy rational expectations asset pricing model with heterogeneous information signals. In each setting the introduction of additional Arrow securities can destabilize the market, causing a bifurcation of the steady state to multiple steady states, periodic orbits or even chaotic fluctuations