World markets for petroleum and other liquid fuels have entered a period of dynamic change-in both supply and demand. Potential new supplies of oil from tight and shale resources have raised optimism for significant new sources of global liquids. The potential for growth in demand for liquid fuels is focused on the emerging economies of China, India, and the Middle East, while liquid fuels demand in the United States, Europe, and other regions with well-established oil markets seems to have peaked. After a long period of sustained high oil prices, improvements in conservation and efficiency have reduced or slowed the growth of liquid fuels use among mature oil consumers. The changes in the overall market environment have led the U.S. Energy Information Administration (EIA) to focus on reassessing long-term trends in liquid fuels markets for the 2014 edition of its International Energy Outlook (IEO2014).IEO2014 projections of future liquids balances include two broad categories: crude and lease condensate and other liquid fuels. Crude and lease condensate includes tight oil, shale oil, extra-heavy crude oil, field condensate, and bitumen (i.e., oil sands, either diluted or upgraded). Other liquids refer to natural gas plant liquids (NGPL), biofuels (including biomass-to-liquids [BTL]), gas-to-liquids (GTL), coal-to-liquids (CTL), kerogen (i.e., oil shale), and refinery gain.After the oil crises of the 1970s and 1980s, much of the debate about world oil markets centered on the limitations of supply. Energy security was (and remains) a major concern, with large resource deposits located in and controlled by members of the Organization of the Petroleum Exporting Countries (OPEC). In addition, strong increases in demand for oil and a limited supply response to rising prices in the mid-2000s led to increasingly vocal concerns about resource depletion. More recently, with higher sustained world oil prices-by historic measures-and advances in extraction technologies, growing supplies of tight oil and shale oil in the United States have brought new resources to market, beginning in North America and, eventually, in other parts of the world. There is also hope that recent legislative changes in Mexico will reverse that country's recent trend of slowly declining oil production. Outside North America, the potential for large production increases in Brazil, Argentina, and elsewhere could help ensure the availability of liquid fuels supplies for many years.