ALTHOUGH the price of oil continues to hit new records, it has in one respect been a quiet week on the oil markets. America's lawmakers are celebrating Independence Day by taking a few days off. That has led to a brief interruption in the torrent of proposals aimed at curbing speculation.

Ten different bills on the subject are in the works in Congress. Before the House of Representatives shut up shop, it approved one by a vote of 402-19. America's politicians are not the only ones to have fingered speculators for the feverish rise in the price of oil and other raw materials. Italy's finance minister believes that there is a “magnum of speculative champagne” included in the price of each barrel. Austria wants the European Union to impose a tax on speculation. Saudi Arabia and other big oil producers routinely blame the price on frothy markets, rather than idle wells.

The accusers point to the link between the volume of transactions on the futures markets and the price of oil. Since 2004 the near tripling of trading in oil on the New York Mercantile Exchange (NYMEX), the world's biggest market for the stuff, has neatly coincided with a tripling in the price.

What is more, investing in oil has become something of a fad. Commodities traders and hedge funds with long experience have been joined by less expert sorts, including pension funds and individuals. All this, the theory runs, is contributing to a bubble in commodities. The rush of punters betting on higher prices is begetting a self-fulfilling prophecy: it is the tide of new investment, rather than inadequate supply or irrepressible demand, that is pushing the price of oil ever higher.

Follow the oil, not the futures

This reasoning holds obvious appeal for those looking for a scapegoat. But there is little evidence to support it. For one thing, the surge in investment in oil futures is not that large relative to the global trade in oil. Barclays Capital, an investment bank, calculates that “index funds”, which have especially exercised the politicians because they always bet on rising prices, account for only 12% of the outstanding contracts on NYMEX and have a value equivalent to just 2% of the world's yearly oil consumption.

More importantly, neither index funds nor other speculators ever buy any physical oil. Instead, they buy futures and options which they settle with a cash payment when they fall due. In essence, these are bets on which way the oil price will move. Since the real currency of such contracts is cash, rather than barrels of crude, there is no limit to the number of bets that can be made. And since no oil is ever held back from the market, these bets do not affect the price of oil any more than bets on a football match affect the result.

The market for nickel provides a good illustration of this. Speculative investment in the metal has been growing steadily over the past year, yet its price has fallen by half. By the same token, the prices of several commodities that are not traded on any exchanges, such as iron ore and rice, have been rising almost as fast as that of oil.

Speculators do play an important role in setting the price of oil and other raw materials. But they do so based on their expectations of future trends in supply and demand, not on whims. If they had somehow managed to push prices to unjustified heights, then demand would contract, leaving unsold pools of oil.

The futures market does sometimes signal that prices are likely to rise, which might prompt speculators to hoard oil in anticipation. But it is not signalling that at the moment, and there is no sign of hoarding. In the absence of rising stocks, it is hard to argue that the oil markets have lost their grip on reality.

Some claim that oil producers are in effect hoarding oil below the ground. But there is also little sign of that, either among companies or countries: all big exporters bar Saudi Arabia are pumping as fast as they can.

It takes two to contango

Despite their dismal reputation, the oil speculators provide a vital service. They help airlines and other big oil consumers to hedge against rising prices, and so to reduce risk—a massive boon amid the economic turmoil. By the same token, they provide oil producers with more predictable future revenues, and so allow them to expand more confidently and borrow more cheaply. That, in turn, should help to lower the price of oil in the long run. Any attempt to curtail speculation, by contrast, is likely to make life harder for firms and oil more expensive.