Motivated by strong comovement and increasing volatility of energy and agricultural prices, we examine dynamic evolutions of ethanol, gasoline, and corn prices over the period of March 2005-March 2011. A structural change is found around March 2008 in the pairwise dynamic correlations between...

Despite an extensive literature on contributing factors to the high commodity prices and volatility in the recent years, few have examined these causal factors together in one analysis. We quantify empirically the relative importance of three factors -global demand, speculation, and energy...