By Carl Levin Guest Columnist As winter approaches, Michigan families will once again face daunting heating bills. Come spring, concerns will shift from the cost of heat to the price we pay at the pump for spring and summer travel. Our manufacturers, too, constantly worry about the cost of energy, as well as the cost of steel and other materials. What do all these examples have in common? Each shows how commodity prices \u2013 for natural gas, gasoline, metals, corn, wheat and other products \u2013 hit every family and business. At a recent hearing of the Senate Permanent Subcommittee on Investigations, which I chair, we exposed how excessive speculation in the markets for these commodities pushes up prices and hurts farmers, businesses and consumers. Very few of us deal directly with the commodities markets, but they are an incredibly important part of our economy, and prices on these markets affect all of us. They are the framework within which producers and users of energy, crops and other commodities buy and sell these goods at prices set by the forces of supply and demand. These markets also enable those affected by the price of commodities to hedge their risks. For example, airlines may use commodity markets to protect themselves from big jumps in the price of jet fuel. But over the last decade or so, these markets have increasingly become the domain of another group: speculators who don\u2019t produce or use the commodities they trade, but seek to profit from the ups and downs in prices. These speculators have become such big players that they have distorted markets, disconnecting the price of commodities from the forces of supply and demand, profiting from price changes and doing great harm to consumers and job-creating companies. At our hearing, experts testified that in some commodities markets, 70 to 90 percent of the trading is now done not by users of commodities, but by speculators. Take crude oil prices, for example, which over the last four months jumped up to $114 a barrel, plunged to $77, and then leaped back up to $95, not because of normal supply and demand, but because hordes of speculators bet on prices. A report by the Consumer Federation of America estimated that speculation now adds about $30 of the price of a barrel of oil and about $600 to the average household\u2019s annual gasoline costs. The price spikes that these speculators engineer threaten our economic recovery. Wild swings in the prices of these commodities make it harder for companies to grow, hire new workers and reduce unemployment. The hearing also exposed how some speculators have done an end-run around regulations designed to limit their domination of commodity markets by using offshore shell corporations. Last year, Congress sought to rein in excessive speculation. In the Dodd-Frank Wall Street Reform and Consumer Protection Act, we toughened what are known as \u201cposition limits\u201d \u2014 restrictions on how much a market participant can dominate the market for a commodity. For the first time, we required the Commodity Futures Trading Commission, the federal agency that regulates these markets, to set position limits on all financial instruments used by speculators. The CFTC is responsible for producing regulations to implement the law. Those regulations, finalized in October, establish position limits, as the law requires, to \u201cdiminish, eliminate or prevent\u201d excessive speculation, and remove some roadblocks that prevented regulators from acting against speculators in the past. But they don\u2019t do enough to limit how some speculators place bets on multiple commodities at once and use those bets to push up prices. In addition, the regulations give speculators another year before the new limits kick in. At our hearing, I pressed the CFTC to do more on these points. American families and businesses can no longer afford the cost of excessive speculation. Until effective position limits are actually in place, our economy will remain vulnerable to chaotic price swings that benefit speculators at the expense of American consumers and businesses. Carl Levin is the senior U.S. senator from Michigan.