A notion of ''behavioral heterogeneity'' of a finite population of households is modelled. It is shown that the higher the degree of behavioral heterogeneity the less sensitive depends the aggregate consumption expenditure ratio upon prices.As a consequence, behavioral heterogeneity implies a...

The following question is analyzed: under what circumstances can one a stable (i.e., time invariant) functional relationship which links aggregate consumption in period t with aggregate income in period t and another "determinants" of consumtion that refer to periods prior to period t and can be...

The paper is about the economic modelling of aggregate consumption expenditure with particular emphasis on the distribution effects of income. Under certain assumptions on the evolution over time of the population of households ("structural stability") we shall derive a first order approximation...

This paper proposes a new explanation for the smile and skewness effects in implied volatilities. Starting from a microeconomic equilibrium approach, we develop a diffusion model for stock prices explicitly incorporating the technical demand induced by hedging strategies. This leads to a...

We provide three characterizations of the minimal martingale measure P associated to a given d- dimensional semimartingale X. In each case, P is shown to be the unique solution of an optimization problem where one minimizes a certain functional over a suitable class of signed local martingale...

Let X be a seminmartingale and Teta the space of all predictable X-integrable processes teta such that integral tetat dX is inthe space S square of semimartingales. We consider the problem of approximating a given random variable H element of L square (P) by the sum of a constant c and a...

We study the problem of convergence of discrete-time option values to continuous-time option values. While previous papers typically concentrate on the approximation of geometric Brownian motion by a binomial tree, we consider here the case where the model is incomplete in both continuos and...