DannyB2B, Thanks for this comment. I would also think that, on the international markets for commodities, financial speculation probably plays a role. I would think that the role would especailly be to amplify price movements. I am not sure whether financial speculation can prop up commodity prices over very long periods. After the 2007/8 commodity price spike, many empirical studies have tried to estimate the impact of financial speculation. Actually, most empirical studies have had a hard time finding clear evidence of such impact. One likely reason for that is that, despite all the short term noise, often the financial speculation actually reflects fairly rational expectations regarding the real market dynamics.