Goodbye to the dollar? But timing is everything.

• Author: Rogoff, Kenneth

As the world's financial leaders meet in Washington this April at the World Bank-International Monetary Fund annual meeting, perhaps they should be glad there is no clear alternative to the dollar as the global currency standard. If the euro were fully ready for prime time, we might well be seeing its dollar exchange rate jump to over $2.00, and not just to $1.65 or $1.70, as it seems poised to do anyway. You can't treat your customers as badly as the United States has done lately if they can go elsewhere.

Over the past six years, the value of the trade-weighted dollar has fallen by more than a quarter, as the United States has continued to rack up historically unprecedented trade deficits. With a soft economy, a badly compromised financial system, and serious concerns about rising inflation, the long-term dollar trend is downward, however the current crisis ends. And it is not over.

The Federal Reserve's bailout of the financial system is unlikely to stand up unless banks find fresh capital, and lots of it. Ultra-rich sovereign wealth funds have the cash to rescue U.S. banks. But they are unlikely to want to do so at this point, even if the U.S. political system allowed it. Instead, as the credit crunch and housing price decline continue, an epic mortgage bailout appears increasingly likely, possibly costing U.S. taxpayers a trillion dollars or more. The problem is that after so many years of miserable returns on dollar assets, will global investors really be willing to absorb another trillion dollars in U.S. debt at anything near current interest rates and exchange rates?

U.S. debt hardly looks like a bargain right now, even without the sinking dollar. Far-flung military misadventures continue to stretch the country's fiscal resources, with costs potentially running into many trillions of dollars, according a recent study by Linda Bilmes and Joseph Stiglitz.

Next year will almost certainly see a massive rise in U.S. corporate defaults, even though many firms entered the recession with relatively strong balance sheets. State and municipal finances are in even worse shape. With tax revenues collapsing due to falling home prices and incomes, dozens of U.S. municipalities could well go into receivership, as New York City did in the 1970s. U.S. municipal bonds are already trading at huge risk premia, and the first big government default hasn't even hit yet.

Of course, if the dollar were to fall off its perch as the world's dominant currency...