The main tools and cocepts of financial and actuarial theory are designed to handle standards, or even small risk. The aim of this paper is to reconsider some selected financial problems, in a setup including infrequent extreme risks. We first consider investors maximizing the expected utility...

The Wishart Autoregressive (WAR) process is a dynamic model for time series of multivariate stochastic volatility. The WAR naturally accommodates the positivity and symmetry of volatility matrices and provides closed-form non-linear forecasts. The estimation of the WAR is straighforward, as it...

The Wishart Autoregressive (WAR) process is a multivariate process of stochastic positive definite matrices. The WAR is proposed in this paper as a dynamic model for stochastic volatility matrices. It yields simple nonlinear forecasts at any horizon and has factor representation, which separates...

We develop a unified approach with closed-form solutions for pricing bonds, stocks, currencies and their derivatives. The specification assumes a fundamental risk factor represented by a stochastic positive definite matrix following a Wishart autoregressive (WAR) process. By assuming a...

The goal of this paper is to assess, for the first time, the empirical impact of "Kaynes' beauty contest", or "higher order belief", on asset price volatility. The paper shows that heterogeneous expectations induce higher order beliefs and that heterogeneous expectation asset pricing models...

We consider a two-sided buyers & sellers' market with indiviseble goods. Agents may trade many units of any of the items available. Previous research, documenting the case ofunit-flow trades, showed that the existence of substitutability or complementarity colligations between goods. These...

These research addressess whether geographic diserfication provides benefits over industry diversification in a sample of European country and industry indexes.The methodology allows performance comparison with short-slling constraints, upper and lower bounds, and many bechmarks. In the absence...