“In the past few years, the United States has experienced a rapid increase in natural gas production from shale resources and oil production from shale and other tight resources. This game-changing development has resulted in a significant reduction in the price of natural gas in the United States, both in absolute terms and compared with prices in other major consuming countries, as well as a significant decline in U.S. dependence on imported petroleum. Recent U.S. production growth has centered largely in a few key regions and has been driven by advances in the application of horizontal drilling and hydraulic fracturing technologies. Given the importance of drilling productivity trends as a driver for future domestic production, EIA has been developing new approaches to assess the productivity of drilling operations.”