The legislation, a variety of economists say, is helping an economy in free fall a year ago to grow again and shed fewer jobs than it otherwise would. Mr. Obama’s promise to “save or create” about 3.5 million jobs by the end of 2010 is roughly on track, though far more jobs are being saved than created, especially among states and cities using their money to avoid cutting teachers, police officers and other workers.

“It was worth doing — it’s made a difference,” said Nigel Gault, chief economist at IHS Global Insight, a financial forecasting and analysis group based in Lexington, Mass…

In interviews, a broad range of economists said the White House and Congress were right to structure the package as a mix of tax cuts and spending, rather than just tax cuts as Republicans prefer or just spending as many Democrats do. And it is fortuitous, many say, that the money gets doled out over two years — longer for major construction — considering the probable length of the “jobless recovery” under way as wary employers hold off on new hiring.

But there are criticisms, mainly that the Obama team relied last winter on overly optimistic economic assumptions and oversold the job-creating benefits of the stimulus package.