Is the Federal Debt Unsustainable?
By general agreement, the federal budget is on an “unsustainable path.” Try typing the phrase into Google News: 19 of the first 20 hits refer to the federal debt. But what does this actually mean? One suspects that some who use the phrase are guided by vague fears, or even that they don’t quite know what to be afraid of. Some people fear that there may come a moment when the government’s bond markets would close, forcing a default or “bankruptcy.” But the government controls the legal-tender currency in which its bonds are issued and can always pay its bills with cash. A more plausible worry is inflation—notably, the threat of rising energy prices in an oil-short world—alongside depreciation of the dollar, either of which would reduce the real return on government bonds. But neither oil-price inflation nor dollar devaluation constitutes default, and neither would be intrinsically “unsustainable.”
After a brief discussion of the major worries, Senior Scholar James Galbraith focuses on one, and only one, critical issue: the actual behavior of the public-debt-to-GDP ratio under differing economic assumptions through time. His conclusion? The CBO’s assumption that the United States must offer a real interest rate on the public debt higher than the real growth rate by itself creates an unsustainability that is not otherwise there. Changing that one assumption completely alters the long-term dynamic of the public debt. By the terms of the CBO’s own model, a low interest rate erases the notion that the US debt-to-GDP ratio is on an “unsustainable path.” The prudent policy conclusion? Keep the projected interest rate down. Otherwise, stay cool: don’t change the expected primary deficit abruptly, and allow the economy to recover through time.