Pietro Dindo

Survival in Speculative Markets

In this paper, I consider an exchange economy with complete markets where agents have heterogeneous beliefs and, possibly, preferences, and investigate the Market Selection Hypothesis that speculation rewards the agent with the most accurate beliefs. First, on the methodological level, I derive the relative consumption dynamics as a function of agents’ effective discount factors, related to consumption decisions across time, and agents’ effective beliefs, related to consumption decisions across states. Sufficient conditions for agents’ survival, either in isolation or in a group, depend on the relative size of effective discount factors and on the relative accuracy of effective beliefs. Then, I show that in economies where agents maximize an Epstein-Zin utility the Market Selection Hypothesis fails: there exist parametrizations where the agent with correct beliefs vanishes and parametrizations where beliefs heterogeneity persists in the long run. Results are robust to local changes of beliefs, risk preferences, and the aggregate endowment process. These failures are shown not to occur when agents’ Epstein-Zin utility has a subjective expected utility representation due to an interdependence of effective discount factors and effective beliefs.

An evolutionary model of firms' location with technological externalities

In an economic geography model where both a negative pecuniary and a positive technological externality are present, we introduce an explicit dynamics of firms locational choice and we characterize its long run distribution. Our analysis shows that economic activities evenly distribute when the pecuniary externalities prevail, and agglomerate otherwise. Due to the stochastic nature of the dynamics, even when agglomeration occurs, it is only a metastable state. By giving time and firms heterogeneity a role, we are bringing the evolutionary approach inside the domain of economic geography.

The Wisdom of the Crowd in Dynamic Economies

The Wisdom of the Crowd applied to financial markets asserts that prices represent a consensus belief that is more accurate than individual beliefs. However, a market selection argument implies that prices eventually reflect only the beliefs of the most accurate agent. In this paper, we show how to reconcile these alternative points of view. In markets in which agents naively learn from equilibrium prices, a dynamic Wisdom of the Crowd holds. Market participation increases agents’ accuracy, and equilibrium prices are more accurate than the most accurate agent.