The United States economy produced roughly $15 trillion worth of goods and services in 2008, making it easily the largest in the world. China is next, at about $ 12 trillion, according to one widely used estimate. Per person, the American economy has the fourth largest output—more than $45,000 for every man, woman and child, on average—behind Luxembourg, Bermuda and Liechtenstein, all havens for offshore banking. In 2007, the American economy began to slow significantly, mostly because of a real-estate slump and related financial problems. In December 2007, the economy entered a recession, according to a committee of academic economists, overseen by the National Bureau of Economic Research, that is widely considered the arbiter of recessions. The committee defines a recession as a broad-based and protracted downturn in economic activity, and its members typically wait many months before announcing that a recession has ended. By nearly all accounts, the recession continued into early 2009, making it the longest one in decades. The economy was last in recession in 2001. Contrary to widespread belief, the terrorist attacks of 2001 did not cause the downturn that year. The economy slowed as the dot-com bubble started leaking in early 2000 and began to shrink in early 2001. The recession ended in November 2001. Over the last few decades, recessions have become less common than they once were. Ben S. Bernanke, the Federal Reserve chairman, and others have described this development as the "great moderation". While the economy used to swing between expansion and contraction every few years, there had been only two relatively brief recessions over the last 25 years before the current downturn. Perhaps the most important reason for the change is the new flexibility of businesses. Executives can now track the ups and downs of their sales and inventories more closely than they used to, thanks in large part to computers. Better transportation, like FedEx, also helps companies to keep their warehouses lean. So a company is less likely to find itself suddenly stuck with too many workers and products—and then have to make sharp cutbacks. Yet there are also now increasing worries that a boom in consumer spending, helped along by more consumer debt, played a large role in lifting economic growth—and moderating its swings—over the last generation. If this is the case—and if the end of the debt boom leads to slower consumer spending, as seems to be happening—economic growth may slow significantly in coming years, even after the recession ends.

单选题 It is implied in the text that the United States is ______.

单选题 The economic recession in the United States ______.

单选题 The last economic recession in 2001 in the U. S.______.

单选题 Economic recessions have become fewer since______.

单选题 The author suggests that______contributes to economic growth.