So as promised (or threatened), my thinking is that futures trading will improve stability. I am not generally a fan of derivatives voodoo. (I like a quote I heard that described them as WMD - can't remember who by).
My justification is a bunch of academic research from the Federal Reserve of Minneapolis in 1986, which is pretty heavy, but if I understand it well enough make a good case for improving stability when the shocks only come from the demand side:
Kawai considers the case of speculation through futures trading in storable commodities. He uses a mean-variable framework in which agents have homogenous beliefs. He finds that if the primary source of randomness in the commodity market is through disturbances to consumption demand, then the introduction of futures market will stabilize spot prices; on the other hand, if the inventory demand disturbance is the preponderant shock, futures trading tends to destabilize prices.http://minneapolisfed.contentdm.oclc.org/cdm/singleitem/collection/p15334coll1/id/397/rec/5I would be interested if any maths geeks out there can validate my interpretation of the report.