Usually defined as a contraction in the Gross National Product that lasts six months or longer. A recession might be marked by job layoffs and high unemployment, stagnant wages, and reductions in retail sales, and slowing of housing and car markets. A recession is much milder than a depression, and is often considered a normal part of the business cycle. In recent years, the U.S. economy has been in recession several times, in 1990-91, 2001, and 2007-2009. The recession of 2007-09 was the most serious of these, and is sometimes referred to as the Great Recession.