The National Bureau of Economic Research declared Monday that the U.S. has been in a  recession since last December.

While it may now be official, the announcement hardly came as news to economists and consumers.

“We’ve been saying this since February or March,” said Gus Faucher, director of macroeconomics at Moody’s Economy.com. “It’s been pretty obvious for a while.”

Faucher cited as evidence payroll employment numbers that have been falling every month since January. Private sector employment payroll figures have declined every month since last December, he added.

These figures have been indicating for months “that firms are cutting back and that they are producing less,” said Faucher.

A recession is traditionally defined as two consecutive quarters of economic contraction.

The NBER, a private group of leading economists, also cited declining employment numbers as a key indicator that the recession began nearly a year ago.

“The committee views the payroll employment measure, which is based on a large survey of employers, as the most reliable comprehensive estimate of employment,” the NBER said in a statement that accompanied its announcement. “This series reached a peak in December 2007 and has declined every month since then.”

An estimated 1.2 million jobs were shed through the first 10 months of 2008, according to the U.S. Labor Department. It’s likely another 300,000 were lost in November.

The NBER said in its statement that a 73-month expansion that began in November 2001 reached its peak last December.

“The committee identified December 2007 as the peak month, after determining that the subsequent decline in economic activity was large enough to qualify as a recession,” according to the NBER’s statement.

The group defines a recession as “a significant decline in economic activity spread across the economy, lasting more than a few months, normally visible in production, employment, real income, and other indicators.”

White House spokesman Tony Fratto said in response to the announcement, “As we’ve always said, NBER determines the start and end dates of business cycles, and they’ve done that. But what’s important is what is being done about it. The most important things we can do for the economy right now are to return the financial and credit markets to normal, and to continue to make progress in housing, and that’s where we’ll continue to focus. Addressing these parts of the economy will help to return the economy to economic growth.”

NBER spokeswoman Donna Zerwitz said several key economic trends -- payroll employment, real manufacturing and wholesale-retail trade sales -- reached their peaks between November 2007 and January 2008.   

To determine when a recession began, the NBER has to consider all these different economic factors and then take into account the fact that these numbers are often revised when new information comes to light.

Using all of the revised numbers, the NBER looks back and pinpoints the exact month when the recession began.

It’s a difficult job given all the moving parts, said Zerwitz.

“They don’t all have to turn around at the same time. It has to be a preponderance of the numbers, or evidence of a trend,” she said.

Faucher said the NBER’s attention to detail is well-placed.

“They want to make very sure that the economy is indeed contracting. It’s a big thing and they want to be very cautious.”