We express the idea of classical competition in a statistical equilibrium model, where the tendency for competition to equalize profit rates results in an exponential power (or Subbotin) distribution. The model supports and extends recent evidence on the Laplace distribution of growth rates in...

We derive microscopic foundations for a well-known probabilistic herding model in the agent-based finance literature. Lo and behold, the model is quite robust with respect to behavioral heterogeneity, yet structural heterogeneity, in the sense of an underlying network structure that describes...

We argue that the complex interactions of competitive heterogeneous firms lead to a statistical equilibrium distribution of firms' profit rates, which turns out to be an exponential power (or Subbotin) distribution. Moreover, we construct a diffusion process that has the Subbotin distribution as...

Kirman’s “ant model” has been used to characterize the expectation formation of financial investors who are prone to herding. The model’s original version suffers from the problem of N-dependence: its ability to replicate the statistical features of financial returns vanishes once the...

A growing body of literature reports evidence of social interaction effects in survey expectations. In this note, we argue that evidence in favor of social interaction effects should be treated with caution, or could even be spurious. Utilizing a parsimonious stochastic model of expectation...

We perform a careful spectral analysis of the correlation structures observed in real and financial returns for a large pool of long-lived US corporations, and find that financial returns are characterized by strong collective fluctuations that are absent from real returns. Once the excessive...