To get an idea of how much those government rebate checks have spurred spending—and who’s benefiting from the buying—business school professors Jonathan Parker (Northwestern) and Christian Broda (University of Chicago) analyzed the spending of 30,000 rebate-receiving households. Using data provided by ACNielsen’s Homescan, whose participants scan the barcodes on their purchases into a database, the researchers found the rebates “clearly have increased household spending,” Parker says. Lower-income households boosted consumption most—spending 6% more, compared with a 3.5% rise across all households.