“ In the fourth quarter of 2008, our economic inputs were wrong. So forecasts using those inputs to make predictions about the future produced answers that were also wrong. That says nothing about whether the stimulus worked or failed. It’s like questioning modern medicine because a case of pneumonia initially presented as strep throat. The recession could have been more than twice as deep as anyone thought in late-2008 and, separately, stimulus is a failed policy idea. But the fact that the initial projections were wrong can’t form the basis for your case.”
— Ezra Klein
