Robustness and Pricing with Uncertain Growth

Abstract

. We develop models of robust decision-making and pricing when there are contemporaneous big and small shocks. We illustrate these models using a stochasticgrowth economy. Large shocks are infrequent changes in the technological growth rate, and small shocks are continuous movements in the technology process. Large shocks evolve as a Markov jump process whereas small shocks are a Brownian motion. Robust decision-making is formalized as a two-player game. In contrast to rational expectations agents, our investors are decision-makers who treat models as approximations and fear misspecication. As an algorithmic device to enforce robustness, investors imagine a second, malevolent player, who has the ability to perturb the baseline model. We study two economies, each of which decentralizes a robust resource allocation problem with hidden growth rates. The economies dier in the manner in which the the model is viewed as an approximation. We compare the pricing implications to those that em...