As I have argued (repeatedly, endlessly, ad nauseam, I know!), our real national debt is not that $14.3 trillion we always hear about, but more like $140 trillion. Another thing to keep in mind: That $14.3 trillion is not just one national debt, but four of them.
There are two flavors of national debt: debt held by the public and intragovernmental debt. The first category — securities held by investors, basically — is the one we mostly worry about. (I worry about the other one, too, but that’s another story.) If I may be permitted to express it in its full glory, the debt held by the public as of April 15 amounts to $9,679,202,714,701.01. (Love, love, love that penny on the end — can’t say Treasury isn’t minding the details! Wasn’t it Ben Franklin who said, “Mind the pennies and the trillions will take care of themselves”? Or something like that?)
That debt held by the public is really four debts, because we have four main ways of financing our borrowing: Treasury bills, Treasury notes, Treasury bonds, and Treasury Inflation Protected Securities (TIPS). Bills are the shortest-term security, the attention-deficit-disorder case of the U.S. sovereign-debt world, maturing in one year or less. Notes, like liberal-arts graduates, mature in one to ten years, and bonds, like a mortgage (remember mortgages?), go from 20 to 30 years. TIPS are a mixed bag, in five-year, ten-year, and 30-year versions. TIPS are a relatively new thing, having been introduced in 1997. They’ve grown popular, from accounting for $33 billion of the national debt in their first year to $640 billion as of March 2011.
Now, when you’ve got $9,679,202,714,701.01 in debt floating around out there in the marketplace, and you’ve got S&P sort of frowning in a meaningful way at your ledger, and bond funds are wishing you the very best of British luck as they dump your debt and refuse to buy any more, but you just can’t help yourself and have to buy a shiny new windmill whenever you see one — in that sort of a situation, you might be keenly interested in how much of your debt is financed through short-term bills vs. how much is locked into 20- or 30-year rates with the long bond. We are starting to have that discussion just now. And it ain’t pretty: The average maturity is 59 months, and about $1.7 trillion of the publicly held debt is in short-term notes, which presents real, sobering risks of the standing-on-a-ledge variety should interest rates spike up.
Here’s the thing: It costs more to finance your debt with 30-year bonds than with 30-day bills. (Yeah, I know, they’re 28-day bills, but cut a poet some slack.) That’s because investors, like men with options, are commitment-shy. If you’re going to lock your investment down for 20 or 30 years, you want a pretty high rate of return. But for 28 days? Less so. But there’s a tradeoff: Interest rates change, sometimes dramatically and often unexpectedly. When the 28-day bill comes up and you still haven’t balanced the budget, you have to refinance that debt. Ben Bernanke and Ramesh Ponnuru are working hard to keep Washington’s short-term borrowing rate at basically zero right now, so there’s a lot of incentive to use short-term rather than long-term financing. Sometimes that works out well: The Clinton administration pushed a lot of our debt into shorter-term instruments back in the 1990s and helped save a bundle on borrowing costs. (The other way to save a bundle on borrowing costs: Stop borrowing.) But sometimes taking the short-term deal and leaving yourself open to unexpected changes in debt-service costs is really, really stupid: Ask somebody who signed up for one of those brilliant adjustable-rate mortgages that take you from free money to pawn-shop rates overnight. A lot of people, myself included, worry that we’ve got too much short-term debt and should use more long-term financing to protect ourselves from interest-rate risk, even if it costs more to do so. Why? Because debt service is one of those checks the government absolutely has to write, and you don’t want surprises. That’s how you get the sort of fiscal crisis that leaves you with banana-republic finances while the Canadians laugh at you.
Incidentally, the Obama administration may be the world-champion deficit spenders, but maturity rates actually hit their low during the Bush administration: In 2008, average maturity was only 48 months. In 2000, long-term bonds accounted for 21 percent of the total debt; by 2009, bonds were down to just under 10 percent of the debt. They’ve climbed a bit since then, up to 10.3 percent. (If you want to check my math, there’s a spreadsheet o’ Treasury figures here.)
The real action seems to be in the medium range, in the notes: In 2008, we owed about $2.8 trillion on those; by 2010 it was $5.6 trillion, and it was $5.8 trillion as of March 2011. Let’s hope we get our finances in order before those come due.