The shrinking government is a normal response to an extraordinary situation. Government spending generally rises during recessions and falls as the economy recovers. Spending always declines at the end of one war, let alone two. And three years after a recession, the American economy typically is restored to full bloom.

But this time is different. Growth has remained sluggish and millions remain unemployed even as the federal government, riven by partisan differences, has largely turned its attention to deficit reduction.

Mr. Bernanke, like many critics of sequestration, said the government could not ignore the need to reduce its annual deficits and curtail the growth of its debt. But he said short-term cuts would worsen those problems by slowing the economy. Moreover, sequestration mostly spares Medicare and Medicaid, the health care programs that are the primary reason federal spending is projected to increase.

Congress and the administration, he said, should “introduce these cuts more gradually and compensate with larger and more sustained cuts in the future.”

Others, however, say that it makes no sense to postpone inevitable cuts. They note that government cutbacks may cause short-term pain, but also tend to provide long-term benefits by making resources available to the private sector.

“People focus on the upfront cost and they don’t think through the whole timeline,” said Tyler Cowen, an economist at George Mason University and an occasional contributor to the Sunday Business section of The New York Times. “You have to cut spending within the next 10 years anyway. It may be time to take some lumps.”

The current round of austerity does not yet approach the depth or the duration of the earlier round of cutbacks. Between 1969 and 1974, as spending on the Vietnam War declined, the government reduced consumption and investment by 24 percent after adjusting for inflation. Between 1991 and 1999, the government reduced consumption and investment by an inflation-adjusted 14 percent.