New research by Broda/Parker suggests the answer is "yes". The rebate checks seem to have increased consumption.

Did the 2008 US tax rebates work? | vox - Research-based policy analysis and commentary from leading economists

This spring, the US government handed out $100 billion in tax rebates. Twentieth century economic thinking - permanent income hypothesis, Ricardian equivalence, and the like - suggests that most would have been saved, as Martin Feldstein recently argued. Not so. Recent research on microdata shows that the typical family increased spending by 3.5% when the rebate arrived, boosting overall nondurable consumption by 2.4% in 2008Q2. The number should be 4.1% in 2008Q3.

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Conclusion

The Economic Stimulus Act of 2008 was aimed at increasing disposable income temporarily through tax rebates in the hope this would stimulate spending and end or at least mitigate the severity of a US economic slowdown. We find that to a significant extent they succeeded. The stimulus payments are initially being spent at significant rates. These rates are slightly higher than those observed in 2001 when fiscal policy has been credited with helping end the 2001 recession.

stimulus working | Posted August 15, 2008 10:45 AM by John Irons