The lowest oil price in four years will provide stimulus of as much as $1.1 trillion to global economies by lowering the cost of fuels and other commodities, according to Citigroup Inc. Brent, the world’s most active crude contract, closed at $83.78 a barrel in London yesterday. That’s more than 20 percent below its average for the past three years, amounting to savings of about $1.8 billion a day based on current output, Citigroup estimates. Savings will climb to $1.1 trillion annually as the slide cuts costs of other commodities, leaving consumers and companies with extra cash to spend and bolstering growth, according to Ed Morse , the bank’s head of global commodities research in New York. Crude prices are plunging amid signs that OPEC, supplier of 40 percent of the world’s oil, won’t act to eliminate a surplus as global growth slows. Combined supplies from the U.S. and […]