What shape is America's recession?

NEW YORK — Now that it is clear that the United States is in recession, the debate has moved on to whether it will be short and shallow or long and deep — a question that is as important for the rest of the world as it is for the U.S.

The answer depends on the shape of the U.S. recession: if it is short and shallow, sufficient growth elsewhere will ensure only a slight global slowdown. But if the U.S. recession is long and severe, the result could be recession in some countries (Britain, Spain, Ireland, Italy and Japan), and even financial crises in vulnerable emerging-market economies.

In principle, the U.S. recession could end up being shaped like a V, U, W, or L. Which scenario is most likely?