The government stimulus produced very little new economic activity in the US.

Judge the 2009 American Recovery and Reinvestment Act (and related federal stimulus) against authoritative estimates of its effect on US output and employment through mid-2010. Retrospective studies of that period are acceptable. True: the main estimates, such as CBO and leading academic studies, find negligible effects on GDP or jobs. Mostly true: most estimates find small effects (e.g. multipliers well below 1), with a few finding larger ones. Mixed: credible estimates are roughly split between small and substantial effects. Mostly false: the predominant estimates, such as CBO's range of roughly 1.5–4% added to GDP in 2010, find meaningful effects, and the claim leans on a minority of low-multiplier studies. False: estimates consistently find substantial effects, and no credible studies support 'very little'.

Set before the research began.

1. E1 Estimated Impact of ARRA on Employment and Economic Output From July 2010 Through September 2010 Congressional Budget Office · 24 November 2010

   “They raised real (inflation-adjusted) gross domestic product by between 1.4 percent and 4.1 percent,”

2. E2 More Evidence on Why the Stimulus Didn't Work economicsone.com (John B. Taylor) · 30 October 2010

   “However, John Cogan, Volker Wieland, Tobias Cwik, and I found that the multiplier in the case of ARRA was much smaller, around .7. Robert Barro argues that it is zero. So there is debate.”

3. E3 More Evidence on Why the Stimulus Didn't Work economicsone.com (John B. Taylor) · 30 October 2010

   “The example of 1.5 is at the upper range of estimates, and was used in a paper by Christina Romer and Jared Bernstein to estimate the impact of the American Recovery and Reinvestment Act of 2009 (ARRA).”

4. E4 More Evidence on Why the Stimulus Didn't Work economicsone.com (John B. Taylor) · 30 October 2010

   “Despite the gigantic $862 billion stimulus package, the change in government purchases due to ARRA has been immaterial to the economic recovery: government purchases increased by only 2 percent of the $862 billion package ($18 billion).”

The evidence includes one estimate of substantial effects, CBO's 1.4–4.1 percent added to GDP in July to September 2010 (E1), and lower estimates from Taylor (about 0.7) and Barro (zero), which Taylor describes as a debate and against which he calls 1.5 the upper range (E2, E3). It does not show whether the main estimates find meaningful or small effects, which is what the criteria use to separate mostly false from mixed or mostly true.