In economics, a recession is a business cycle contraction that occurs when there is a general decline in economic activity. Recessions generally occur when there is a widespread drop in spending (an adverse demand shock). This may be triggered by various events, such as a financial crisis, an external trade shock, an adverse supply shock, the bursting of an economic bubble, or a large-scale anthropogenic or natural disaster (e.g. a pandemic).

In the United States, a recession is defined as "a significant decline in economic activity spread across the market, lasting more than a few months, normally visible in real GDP, real income, employment, industrial production, and wholesale-retail sales." The European Union has adopted a similar definition. In the United Kingdom, a recession is defined as negative economic growth for two consecutive quarters.

Governments usually respond to recessions by adopting expansionary macroeconomic policies, such as increasing money supply and decreasing interest rates or increasing government spending and decreasing taxation.