Megan McArdle writes,

How much unemployment reduction you get for a given amount of stimulus spending is, obviously, at best an imperfect estimation. But let’s take the CBO’s estimates as representing a rough consensus of those who favor stimulus: for our $800 billion, we got a reduction of 0.7 to 1.8 percentage points.

Full employment is perhaps 4.5-5%. If we assume that stimulus benefits increase linearly, that means we would have needed a stimulus of, on the low end, $2.5 trillion. On the high end, it would have been in the $4-5 trillion range.

Read her whole post.

Robert Barro writes,

For example, the Bureau of Labor Statistics reports that, near the worst of the recession in March 2009, 3.9 million people were hired and 4.7 million were separated from jobs. This net loss of 800,000 jobs in one month indicates a very weak economy–but nevertheless one in which 3.9 million people were hired. A program that reduced incentives for people to search for and accept jobs could surely matter a lot here.

He claims that the unemployment rate would be much lower now if Congress had not passed any extensions of unemployment benefits. I have not gone through his analysis, but I suspect that I, like Alex Tabarrok, would not find it persuasive. Nonetheless, I think there is a case to be made for allowing people to continue to collect unemployment benefits after they find a new job, until their benefits are scheduled to expire. We can argue about how generous the unemployment benefits should be overall, but for any level of benefits it is possible to reduce the disincentive to find work.