"Since the late 1970s, U.S. policymakers at both the federal and state levels have enacted a variety of incentives, regulations, and programs to encourage the production and use of agriculture-based biofuels. Initially, federal biofuels policies were developed to help kick-start the biofuels industry during its early development, when neither production capacity nor a market for the finished product was widely available. Federal policy has played a key role in helping to close the price gap between biofuels and cheaper petroleum fuels. Now, as the industry has evolved, other policy goals (e.g., national energy security, climate change concerns, support for rural economies) are cited by proponents as justification for continuing policy support. The U.S. biofuels sector has responded to these government incentives by expanding output every year since 1996, with important implications for the domestic and international food and fuel sectors. The production of ethanol (the primary biofuel produced in the United States) has risen from about 175 million gallons in 1980 to 10.7 billion gallons per year in 2009. U.S. biodiesel production is much smaller than its ethanol counterpart, but has also shown strong growth, rising from 0.5 million gallons in 1999 to an estimated 776 million gallons in 2008 before being impeded by the nationwide financial crisis."
CRS Report for Congress, R41282