In general usage, the word recession connotes a marked slippage in economic activity. While gross domestic product (GDP) is the broadest measure of economic activity, the often-cited identification of a recession with two consecutive quarters of negative GDP growth is not an official designation. The designation of a recession is the province of a committee of experts at the National Bureau of Economic Research (NBER), a private non-profit research organization that focuses on understanding the U.S. economy. The NBER recession is a monthly concept that takes account of a number of monthly indicators—such as employment, personal income, and industrial production—as well as quarterly GDP growth. Therefore, while negative GDP growth and recessions closely track each other, the consideration by the NBER of the monthly indicators, especially employment, means that the identification of a recession with two consecutive quarters of negative GDP growth does not always hold. For information on recession, or business-cycle, dating, see: http://www.nber.org/cycles/jan08bcdc_memo.html.