Over the last six years, net oil imports have fallen by 33% to average 8.4 million barrels per day (Mb/d) in 2011. This represents 45% of domestic consumption, down from 60% in 2005. Oil is a critical resource for the U.S. economy, but despite policy makers' longstanding concern, U.S. oil imports had generally increased for decades until peaking in 2005. Since then, the economic downturn and higher oil prices were a drag on oil consumption, while price-driven private investment and policy helped increase domestic supply of oil and oil alternatives. Net imports are gross imports minus exports. The decline in net imports has manifested itself as a decrease in gross imports and an increase in exports of petroleum products. Gross U.S. imports of crude oil and petroleum products averaged 11.4 Mb/d in 2011, down 17% since 2005. More than a third of gross imports came from Canada and Mexico in 2011. About 40% came from members of the Organization for the Petroleum Exporting Countries (OPEC), mostly from OPEC members outside the Persian Gulf. Regionally, the largest share of U.S. imports come into the Gulf Coast region, which holds about half of U.S. refining capacity and sends petroleum products to other parts of the country and abroad. All regions of the country import more crude than refined products except for the East Coast, where petroleum products imports may rise further due to refinery closures. U.S. oil exports, made up almost entirely of petroleum products, averaged 2.9 Mb/d in 2011. This is up from export of 1.2 Mb/d in 2005, led by growing export of distillates (diesel and related fuels) and gasoline. More than 60% of U.S. exports went to countries in the Western Hemisphere, particularly to countries such as Mexico and Canada from which the U.S. imports crude oil. Exports occur largely as a result of commercial decisions by oil market participants which reflect current oil market conditions as well as past investment in refining. As a result, net oil imports fell from a peak of 12.5 Mb/d in 2005 to 8.4 Mb/d in 2011, their lowest level since 1995. A consensus is generally emerging among energy analysts that U.S. oil imports may be past their peak, reached in 2005. Imports as a share of consumption are expected to fall further, to less than 40% after 2020 driven by tighter fuel economy standards and increased domestic supply. Despite the decline in net import volumes, the cost of net imports has increased due to rising oil prices. The aggregate national cost of oil imports is a function of the volume of oil imported and the price of that oil. The United States spent about $327 billion on net oil imports in 2011. Being a net importer of a particular good is not necessarily negative for an economy, but greater national oil import dependence can amplify the negative economic impacts of oil price increases. Oil import and export developments pose a host of policy issues. Concerns about import dependence continue to generate interest in policy options to directly discourage imports or to reduce the need for imports by increasing domestic supply and decreasing demand. Rising exports at a time of rising prices has led to calls for policies to restrict such trade. The debate around the Keystone XL pipeline involves concerns about imports, exports, and the environment. The rising cost for fuels has led to calls for release of the Strategic Petroleum Reserve, meant to provide a short term policy option in case of supply disruptions. Policy options may entail various economic, fiscal, and environmental trade-offs.