Chapter 1: The Nation
Reasons to Worry

By NIALL FERGUSON
Published: June 11, 2006
Think of the economy of the United States as a dinosaur — one of those huge herbivores whose bulk shook the ground. A brachiosaur. A brontosaur. A diplodocus. Like them, the U.S. economy is mind-bogglingly enormous — two and a half times as big as the next largest economy in the world and almost as large as that of the six other members of the Group of Seven combined. The catch is that it has to consume almost incessantly to sustain its great heft.

Contrary to what we used to believe, leviathans like the diplodocus were not exactly sloths. It is now thought that they had the strength to stand on their hind legs in order to reach food at the top of trees. They may even have been able to run rather than merely plod. But it seems reasonable to assume that their reaction times were slow; it was a very long way from the diplodocus's tail to its brain. If a predator sank its fangs into that tail, it might have taken the diplodocus a few moments to feel the pain.
The big question about the dinosaurs is, of course, What caused their extinction? Why were so many species unable to evolve in response to environmental changes? The most common explanation is that a very sudden event, like a meteor's impact, gave the dinosaurs too little time to evolve and provided smaller and more dynamic life forms with an opportunity to take over.
An analogous question for economists is whether the United States is capable of evolving out of its present excessive indebtedness. Or could the global economic environment change so drastically as to threaten, if not extinction, then at least decline relative to smaller, more dynamic economies?
When the National Debt clock in Times Square was turned on in 1989, the federal debt amounted to around $2.7 trillion. Eleven years later, on Sept. 7, 2000, the clock read: "Our national debt: $5,676,989,904,887. Your family share: $73,733." That's when the clock was turned off, because, in those innocent days, it seemed as if the $5.6 trillion debt was set to decline, perhaps to disappear altogether. On that same date, CNN reported, "Vice President and Democratic presidential nominee Al Gore . . . outlined a plan that he says would eliminate the debt by 2012." The proposal was uncontroversial. Economic advisers to the Republican candidate, George W. Bush, were said to have "agreed with the principle of paying down the debt," but their candidate had "not committed to a specific date for eliminating it."
That should have set the alarm bells ringing. (And, in fact, the National Debt Clock started running again in 2002.)
Since becoming president, George Bush has presided over one of the steepest peacetime rises ever in the federal debt. The gross federal debt now exceeds $8.3 trillion. There are three reasons for the post-2000 increase: reduced revenue during the 2001 recession, generous tax cuts for higher income groups and increased expenditures not only on warfare abroad but also on welfare at home. And if projections from the Congressional Budget Office turn out to be correct, we are just a decade away from a $12.8 trillion debt — more than double what it was when Bush took office.
Big public debts are not always bad, to be sure. It could be argued that in his first term Bush wisely used fiscal policy to boost aggregate demand and counter the impact of the dot-com bust. Public borrowing also allows "tax smoothing" by spreading out over time the cost of big one-off expenses like wars, three of which the United States has fought since 1999.
On the other hand, by requiring larger interest payments, big public debts devour revenue that could be spent on other programs. They may crowd out private investment by pushing up long-term interest rates. They may also have a regressive distributional impact, transferring economic resources from taxpayers to bondholders or from future generations to the present generation.
It all depends how you measure the debt. If you exclude bonds and bills in the possession of government agencies and programs, like the Social Security trust fund, the debt actually held by private investors is less than $5 trillion. Economists commonly calculate the debt burden as a percentage of gross domestic product. Counting only the debt held by the public, that works out to around 38 percent of G.D.P., a major increase relative to 1981 but still modest compared with the years after World War II. What's more, the C.B.O. forecasts (albeit with the rosy assumption of annual growth close to 5 percent) that the debt-to-G.D.P. ratio will actually decline in the decade ahead, to perhaps as little as 34.5 percent — even if today's lax budgetary plans are adhered to.
The trouble is that the officially stated borrowings of the federal government are only one part of the U.S. debt problem. For it is not only the government's debt that has grown large of late. Ordinary American households have also gone on prodigious borrowing sprees.
In the past five years alone, the value of U.S. home-mortgage debt has increased by nearly $3 trillion. Not all of that borrowing went to pay for real estate, the traditional function of mortgages. In 2004, net mortgage borrowing not used for the purchase of new homes amounted to nearly $600 billion. The International Monetary Fund estimates that this kind of equity extraction has risen from less than 2 percent of household disposable income in the year 2000 to more than 9 percent in the third quarter of last year.