WASHINGTON (Reuters) - The economy slipped into recession in December 2007, the nation's business cycle arbiter declared on Monday, and the downturn could be the worst since World War Two.

全国经济研究局表示，其商业周期定期委员会成员上周五举行电话会议并得出结论认为，始于2001年11月的经济增长开已经结束。这一个时期的经济增长历时10年。

The National Bureau of Economic Research said its business cycle dating committee members met by conference call on Friday and concluded that the economic expansion that started in November 2001 had ended. The previous period of economic expansion, which ended in 2001, lasted 10 years.

许多经济学家预计，衰退将持续穿越明年年中，目前的经济衰退已经是大萧条以来的第三次，其持续时间，仅次于上世纪70年代中期和80年代初的16个月低谷期。

The current recession, which many economists expect to persist through the middle of next year, is already the third-longest since the Great Depression, behind only the 16-month slumps of the mid-1970s and early 1980s.

“我认为我们面临很多困难，这是将可能是一个深刻和长期衰退，”杰弗里弗兰克尔(Jeffrey Frankel)，哈佛大学经济学家, 国家经济研究局的委员会委员，告诉CNBC:“这有可能是最严重的战后经济衰退。我们还不十分清楚。”

"I think that we've got a ways to go, that this is going to be probably a deep and long recession," Jeffrey Frankel, a Harvard University economist who sits on the NBER's committee, told CNBC. "It could be the worst post-War recession. We don't know yet."

将衰退界定于连续两个季度的实际国内生产总值下降，这在许多国家是共识。国家经济研究局没有这样做,相反，它注视于遍布整个经济层面的经济活动下降和连续超过几个月的持续期。
The NBER does not define a recession as two consecutive quarters of decline in real gross domestic product, as is the rule of thumb in many countries. Instead, it looks for a decline in economic activity, spread across the economy and lasting more than a few months.

目前的低迷界定特别棘手，因为国内生产总值在2008年上半年仍然是正数增涨。国家经济研究局表示: 委员会看到就业在2007年12月达到高峰，自那时以来每个月都在下降，委员会同时也看国内生产总值和其他数据，以确认衰退何时开始。

The current downturn was particularly tricky to define because gross domestic product remained positive in the first half of 2008. The NBER said its committee looked at payrolls, which peaked in December 2007 and declined in every month since then, as well as real GDP and other data to determine when the recession started.

“委员会确认，经济活动减少, 在2008年达到了衰退的标准。”国家经济研究局在一份声明中说:“排除了其他含糊不清的季度性产品方面的变动情况, 所有的衡量国内生产的证据都证实了这一结论。”