The National Bureau of Economic Research (NBER) is a private, non-profit organization based in the United States that focuses on conducting economic research. Founded in 1920, it is known for its influential studies on various economic issues, including business cycles, economic growth, and labor markets. The NBER plays a crucial role in providing data and analysis that inform policymakers, researchers, and the public. One of the NBER's key functions is to determine the dates of economic recessions and expansions in the U.S. economy. This is done through rigorous analysis of economic indicators, such as GDP and employment rates. The NBER's findings are widely respected and often serve as a reference for understanding the overall health of the economy.