...In 1981, there were 325 refineries in the U.S. with a capacity of 18.6 million barrels per day. Today, there are 148, with a capacity of about 17 million barrels -- though U.S. demand for gasoline has increased more than 20%.... One explanation for this performance is the historically low gas prices over much of the past 20 years; there has often been little incentive to build new capacity. But just as big a problem are onerous and costly regulatory burdens that have sucked profits from the industry. This includes a permitting process that is subject to endless bureaucratic delay...