In evaluating ARRA, both the Council of Economic Advisors (CEA) and the Congressional Budget Office (CBO) used instead the impacts of direct federal spending and tax relief. These estimates miss the role of states as agents. The authors provide estimates of aid’s multiplier effects allowing explicitly for state behavior, first from an SVAR analysis separating federal aid from federal tax relief, second from a narrative analysis using the political record for unanticipated federal aid programs, and third from constructed macroeconomic estimates implied by an estimated model of state governments’ fiscal choices. The authors reach three conclusions. First, federal transfers to state and local governments are less stimulative than transfers to households and firms. Second, federal aid for welfare spending is more stimulative than is general purpose aid. Third, an estimated model of state government fiscal behavior provides a microeconomic foundation for the observed macroeconomic impacts of aid.