AMERICA’S economy is headed for a major slowdown. Whether there is a recession (two quarters of negative growth) is less important than the fact that the economy will operate well below its potential, and unemployment will grow. The country needs a stimulus, but anything we do will add to our soaring deficit, so it is important to get as much bang for the buck as possible. The optimal package would contain one fast-acting measure along with others that could lead to increased spending if and only if the economy goes into a steep downturn.

We should begin by strengthening the unemployment insurance system, because money received by the unemployed would be spent immediately.

The federal government should also provide some assistance to states and localities, which are already beginning to feel the pinch, as property values have fallen. Typically, they respond by cutting spending, and this acts as an automatic destabilizer. Federal assistance should come in the form of support for rebuilding crucial infrastructure.

More federal support for state education budgets would also strengthen the economy in the short run and promote growth in the long run, as would spending to promote energy conservation and lower emissions. It may take some time to put these kinds of well-designed expenditure programs into place, but this slowdown looks as if it will last longer than some of the other downturns in recent memory. Housing prices have a long way to fall to return to more normal levels, and if Americans start saving more than they have been, consumption could remain low for some time.