Vice President Joe Biden said on a Monday conference call with reporters that it was “above [his] pay grade” to explain in detail the methodology the White House uses to estimate the number of jobs created or saved by the economic stimulus legislation, but stressed that there had been no “reasonable” challenges to the estimates.

During the call, Biden said that the stimulus package, which was signed into law in February, saved or created 150,000 in its first 100 days, and he outlined White House plans to accelerate the pace so that 600,000 more jobs will be saved or created in the second 100 days this summer.

Asked by Jonathan Riskind of the Columbus Dispatch to explain how the White House determined these numbers, Biden said that the Council of Economic Advisers makes its estimates based on measuring what the U.S. employment level would have been without the stimulus, and then comparing it to the nation’s actual employment level. 

“I’m sorry I’m not an economist,” Biden said as he was describing the methodology. “My background is foreign policy and the constitution. “

The White House estimates also consider the number of jobs needed to complete certain projects funded by the stimulus, and take into account the “spinoff effects” of spending programs. For instance, tax credits and subsidies for weatherization of homes and wind farms boost contracts for businesses that may not be receiving stimulus money directly, the vice president, who is spearheading the implementation of the program, said.

“I’m a little above my pay grade here as I try to explain in more detail how they count spinoff effects of actual jobs created, “ Biden said.

“It’s complicated,” he acknowledged. “But the fact is that there has been no challenge to the methodology the Council of Economic Advisers has come up with, known to national economists as being reasonable to the estimates we have as to the actual jobs saved or created.”

Later in the call, he said that while it was hard to take solace in the fact that the unemployment rate has increased to 9.4 percent, Biden insisted it would have been worse without the stimulus legislation.

“There’s no doubt that the unemployment rate would be considerably higher than it is now,” he said. “The estimates range from we would have lost … one million to four million additional jobs depending on whose model you look at, were it not for the Recovery Act.”