On the 30th anniversary of the seminal article by Pindyck (1993), we re-evaluate the evidence for the classical rational model of commodity prices, extending it to admit time- varying discount rates, investors’ heterogeneity or both. Discount factors specifications are flexible enough to allow...

Motivated by repeated price spikes and crashes over the last decade, we investigate whether the rapidly growing market shares of futures speculators have destabilized commodity spot prices. We approximate conditional volatility and regress it on expected and unexpected speculative open interest....