I don't have the skills or resources to research the answer to my question, so I'll lay the question on you:

How big a part in the rise of oil prices is due to commodity futures trading, rather than current supply and demand?

UPDATE: I have located an essay by Raymond P. Learsy, whose bio states that his career was in commodites trading. His argument is that the current price of oil is indeed being manipulated by the futures trading of unkown agents, perhaps OPEC. He offers some evidence. I don't have the skills to do a good analysis of the essay, but, if I were running OPEC, I certainly would do whatever I could to keep prices high and push them higher.

UPDATE 2: Somehow I missed this item before. Congressional Democrats are accusing futures traders of artificially running up the price of oil.

"Legislation has been proposed to make speculation more difficult. But arguing that "rampant speculation" in the oil markets has helped drive up crude prices, Senate Democrats proposed a new measure that would increase the amount of money traders would have to put down when buying oil futures. With gas and oil prices at record levels, it makes no sense to allow this growing bubble of speculation to take place," said Sen. Byron Dorgan, D-N.D., who is championing the measure. "By increasing the margin requirement, we will send a message to speculators that they will no longer be allowed to artificially drive up the price of oil and gas." Currently, traders must put down anywhere between 5 percent and 7 percent when making energy futures trades, compared with 50 percent for stocks. The legislation does not specify how high that new margin requirement should be. It would instruct the Commodity Futures Trading Commission to require a "substantial increase" in the amount.

Sounds like reasonable regulation to me.

UPDATE 3: From England, this editorial in The Mail. Mostly invective without actual argument, to the effect that commodities futures trading is behind the run-up in oil prices. Link from Last of the Few. (Last of the Few is NSFW)

The practice of commodites futures trading raises serious questions. From a Christian point of view, I've had trouble with commodity futures trading. I am more familiar with agriculture than petroleum, so I'll use an example from that area. A commodities trader decides, for whatever reasons, that the price of corn will be higher in 8 months than it is now. So he begins "buying" corn futures at a price lower than he anticipates in 8 months. Let's say he is a big and well-known trader. Others follow his lead. Soon, the current market is responding to the demand and prices rise. (The reverse scenario could also happen.) Prices, therefore, in this example are going up not because of current supply and demand for actual use of corn, but because of forecasts.

And it's not like the traders have any intention of eating the corn they are buying, or feeding it to livestock, or making ethanol. These are purely money-making transactions in which the buyers and sellers never will see the product.

Christian economic theories are not agreed-upon dogma, but most of them stipulate that work done should be honest and needful. Does commodities futures trading meet this criteria? Also, I think most Christian economic theories would hold that price increases should reflect real conditions, not speculative ones, and be related to actual value, not merely market value.

Would Jesus be a commodities futures trader?