http://en.wikipedia.org/wiki/Recession_shapes

Recession shapes

Recession shapes are used by economists to describe different types of recessions. There is no specific academic theory or classification system for recession shapes; rather the terminology is used as an informal shorthand to characterize recessions and their recoveries.^[1]

The most commonly used terms are V-shaped, U-shaped, W-shaped, and L-shaped recessions. The shapes take their names from the approximate shape economic data make in graphs during recessions. The letters can also be applied referring to the recoveries (ie "V-shaped recovery").

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A W-shaped recession or "double dip" recession, occurs when the economy has a recession, emerges from the recession with a short period of growth, but quickly falls back into recession.

The early 1980s recession in the United States is cited as an example of a W-shaped recession. The National Bureau of Economic Research considers two recessions to have occurred in the early 1980s.^[4] The economy fell into recession from January 1980 to July 1980, shrinking at an 8 percent annual rate from April to June of 1980. The economy then entered a quick period of growth, and in the first three months of 1981 grew at an 8.4 percent annual rate. As the Federal Reserve under Paul Volcker raised interest rates to fight inflation, the economy dipped back into recession (hence, the "double dip") from July 1981 to November 1982. The economy then entered a period of mostly robust growth for the rest of the decade.

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