Recession refers to a business cycle contraction when economic activity is in a significant decline. It happens when the GDP rate declines by 2 or more consecutive quarters with a huge fluctuation of monthly indicators like a rise in unemployment. Recession is usually declared by the National Bureau of Economic Research (NBER). It defines a recession as a huge decline in economic activity throughout the economy, which lasts for more than several months and usually visible in real GDP, real income, employment, industrial production, and wholesale-retail sales.