WHY THE STIMULUS WAS LESS EFFECTIVE

(h/t Jon Perr)
The wingnuts used to love to point out that early in his term, Pres. Obama said that the stimulus would keep unemployment under 8%.  I would reply that this prediction was made on the best available knowledge at the time and Ezra Klein has a better answer:

To understand how the administration got it so wrong, we need to look at the data it was looking at.

The Bureau of Economic Analysis, the agency charged with measuring the size and growth of the U.S. economy, initially projected that the economy shrank at an annual rate of 3.8 percent in the last quarter of 2008. Months later, the bureau almost doubled that estimate, saying the number was 6.2 percent. Then it was revised to 6.3 percent. But it wasn’t until this year [2011] that the actual number was revealed: 8.9 percent. That makes it one of the worst quarters in American history. Bernstein and Romer knew in 2008 that the economy had sustained a tough blow; they didn’t know that it had been run over by a truck.