No one illustrated the conversion to fiscal stimulus more vividly than Martin Feldstein, a Harvard economist and a well-known conservative who served for a time as a top economic adviser to President Reagan. In a paper, Mr. Feldstein noted that the usual method of reviving the economy — lower interest rates — was failing to work because of “a dysfunctional credit market.”

That left fiscal stimulus to offset what he described as a decline of $400 billion a year in consumer spending. “While good tax policy can contribute to ending the recession, the heavy lifting will have to be done by increased government spending,” Mr. Feldstein said.

He pushed for big spending, carried out quickly. Among his proposals: replace depleted military supplies and equipment and step up financing for “useful research.” He also said that the shortage of “shovel ready” projects should not be a deterrent in a recession that is likely to last long enough to plan and execute new projects.