Former Obama adviser Christina Romer and David Romer of the University of California, Berkeley, estimate a tax-cut multiplier of 3.0, meaning $1 of lower taxes raises short-run output by $3. Messrs. Mountford and Uhlig show that substantial tax cuts had a far larger impact on output and employment than spending increases, with a multiplier up to 5.0
multiplier???
interesting read:
why-spending-stimulus-failed