While some conservatives remain as skeptical as ever that big increases in government spending give the economy a jolt that is worth the cost, Martin Feldstein, a conservative Harvard economist who served in the Reagan administration, said the problem with the package was that some of its tax cuts and spending programs were of a variety that did little to spur the economy.

“There should have been more direct federal spending that would have added to aggregate demand,” he said. “Temporary tax cuts and one-time transfers to seniors were largely saved and didn’t stimulate spending.”

Image Jalin Willis checked the job listings in Denver last month. The nation's unemployment rate topped 10 percent this month. Credit... Matthew Staver/Bloomberg News

Even the $787 billion price tag overstates the plan’s stimulus value given changes made in Congress, economists say. Nearly a tenth of the package, $70 billion, comes from a provision adjusting the alternative minimum tax so it does not hit middle-income taxpayers this year. That routine fix, which would do nothing to stimulate the economy, was added in part to seek Republican votes. But to keep the package’s overall cost down, provisions that would stimulate the economy  like aid to revenue-starved states and infrastructure projects  got less as a result.

Among Democrats in the White House and Congress, “there was a considerable amount of hand-wringing that it was too small, and I sympathized with that argument,” said Mark Zandi, chief economist of Moody’s Economy.com and an occasional adviser to lawmakers.

Even so, “the stimulus is doing what it was supposed to do  it is contributing to ending the recession,” he added, citing the economy’s third-quarter expansion by a 3.5 percent seasonally adjusted annual rate. “In my view, without the stimulus, G.D.P. would still be negative and unemployment would be firmly over 11 percent. And there are a little over 1.1 million more jobs out there as of October than would have been out there without the stimulus.”

Politically, however, the president is saddled with his original claim that, with the stimulus, the jobless rate would peak at 8.1 percent  a miscalculation that Republicans constantly recall. While the administration has said its economic assumptions were in line with private forecasts, most of which also underestimated the recession’s punch, it was more optimistic than most.