Model Uncertainty and Option Markets in Heterogeneous Economies

Abstract

This paper provides option pricing and volume implications for an incomplete market economy with heterogenous agents who face model uncertainty and disagree on the dividend growth rate. Market incompleteness makes options non-redundant while heterogeneity creates a link between differences in beliefs and option volumes. We solve for both option prices and volumes and test the joint empirical implications using SP500 index option data. We use survey data to build an Index of Dispersion in Beliefs and find that a model which takes into account information heterogeneity can explain the dynamics of option volume better than reduced-form models with stochastic volatility. Moreover, its hedging performance is superior. Finally, we find that the Index of Dispersion in Beliefs is correlated with changes in the shape of the smile and it forecasts future realized volatility even after controlling for the current implied volatility.