By J. Bradford DeLong
The opinions expressed are his own.

Former US Treasury Secretary Lawrence Summers had a good line at the International Monetary Fund meetings this year: governments, he said, are trying to treat a broken ankle when the patient is facing organ failure. Summers was criticizing Europe’s focus on the second-order issue of Greece while far graver imbalances – between the EU’s north and south, and between reckless banks’ creditors and governments that failed to regulate properly – worsen with each passing day.

But, on the other side of the Atlantic, Americans have no reason to feel smug. Summers could have used the same metaphor to criticize the United States, where the continued focus on the long-run funding dilemmas of social insurance is sucking all of the oxygen out of efforts to deal with America’s macroeconomic and unemployment crisis.

The US government can currently borrow for 30 years at a real (inflation-adjusted) interest rate of 1% per year. Suppose that the US government were to borrow an extra $500 billion over the next two years and spend it on infrastructure – even unproductively, on projects for which the social rate of return is a measly 25% per year. Suppose that – as seems to be the case – the simple Keynesian government-expenditure multiplier on this spending is only two.

In that case, the $500 billion of extra federal infrastructure spending over the next two years would produce $1 trillion of extra output of goods and services, generate approximately seven million person-years of extra employment, and push down the unemployment rate by two percentage points in each of those years. And, with tighter labor-force attachment on the part of those who have jobs, the unemployment rate thereafter would likely be about 0.1 percentage points lower in the indefinite future.

The impressive gains don’t stop there. Better infrastructure would mean an extra $20 billion a year of income and social welfare. A lower unemployment rate into the future would mean another $20 billion a year in higher production. And half of the extra $1 trillion of goods and services would show up as consumption goods and services for American households.