Estimation of the covariance matrix is an essential task of portfolio selection. A multivariate approach is needed. Unfortunately, it is leading to a flat likelihood function for a realistic number of assets. This paper is proposing a principal components analysis together with a sophisticated...

We use a simple nonlinear commodity market model to illustrate the impact of recent reforms of the CAP on the variability of EU and world wheat prices. Second, within an expected utility framework we estimate the transfer and risk effects on producer welfare due to market liberalizing reforms....