A recession is a significant decline in economic activity that lasts for months or even years. While there is no official definition of a recession, most commentators and analysts use two consecutive quarters of decline in a countrys real gross domestic product (GDP) as a practical definition. However, this is not the official definition nor the way economists evaluate the state of the business cycle. Instead, both official determinations of recessions and economists assessment of economic activity are based on a holistic look at the data, including the labor market, consumer and business spending, industrial production, and incomes. The National Bureau of Economic Research (NBER) Business Cycle Dating Committee, which is the official recession scorekeeper, defines a recession as "a significant decline in economic activity that is spread across the economy and that lasts more than a few months". The variables the committee typically tracks include real personal income minus government transfers, employment, various forms of real consumer spending, and industrial production. In addition, a widely cited indicator of recessions, the "Sahm rule" named after economist Claudia Sahm, maintains that a recession is likely underway when the three-month moving average of the unemployment rate rises by at least half a percentage point (50 basis points) relative to its lowest point in the previous 12 months.