The current debate over extending the payroll tax cut well demonstrates that policymakers often mean different things when referring to policies that “help” or “expand” the economy. I often hear the words “stimulus” and “growth” used interchangeably, but when economists use them, we typically are making a distinction between different economic goals that apply to different circumstances.
“Stimulus” usually refers to short-term policies to increase demand for goods and services in an economy operating at less-than-full capacity -- i.e., an economy with high unemployment. In such a recessionary economy, the problem is not a lack of productive resources (capital and labor), but a lack of demand for the goods and services that those resources produce. Under such conditions, public sector deficits -- whether through tax cuts or direct spending -- can be an effective way to increase demand (consumption) and the level of economic activity.
“Growth” usually refers to the long-term expansion of the “supply side” of the economy -- that is, the supply of capital and labor. When the economy is at “full employment,” the binding constraint on it is not the demand for goods and services, but the supply of inputs to production. Fiscal policies that are good at growing the economy over the longer term are therefore those...
