When there is an economic downturn, Congress and the President use fiscal policyLOADING... to stabilize real GDP. But the conduct of the fiscal policy involves several time lags, such as the recognition time lag that causes a delay in identification of the economic problem, the action time lag that is caused by the delay in Congressional approval of the policy, and the effect time lag that arises because policy actions take time to exert their full effects on the economy. These time lags could actually cause discretionary fiscal policy to