Contrary to the classic framework of passive strategies, if investors exploit return predictability through active strategies then there is a tension between the mean-variance frontiers that drive empirical work and the mean-variance preferences that are used in finance theory. We show that...

We use the recent introduction of biofuels to study the effect of industry factors on the relationships between wholesale commodity prices. Correlations between agricultural products and oil are strongest in the 2005-09 period, coinciding with the boom of biofuels, and remain substantial until...