what if?How a default would unfold immediately appears relatively straightforward. It's the reaction that no one can predict, because it's never happened before.
The first move will be made by the U.S. Federal Reserve. The Fed is the Treasury Department's bank, handling government cheques and lending to banks which borrow using U.S. Treasury debt as collateral.
One day — the U.S. government has estimated it will be Aug. 2 — the Fed will serve notice on the government that its account at the Fed will be in overdraft by the end of the day, in violation of the Federal Reserve Act.
On Aug. 3, some $23 billion in Social Security benefit payments are due to be processed.
On Aug. 4, the Treasury Department must pay $87 billion to investors to redeem maturing Treasury securities.
On Aug. 15, more than $30 billion in interest payments come due.
In addition to those costs, the government normally pays $5 billion to $10 billion daily to defence contractors, Medicare providers, federal employees and others.
With no authority from Congress to borrow more, the government won't be able to make all its usual payments.
Some suggest the government could pay some of its bills and defer other spending, but given it makes more than 70 million payments a month, that selective payment would be a formidable task.
Regardless of how that issue is resolved, there's no question that government services, programs and benefits could take an enormous hit.
No one knows exactly what spending choices U.S. president Barack Obama and his top officials would make if the crisis comes.
The White House Office of Budget and Management is the agency charged with reviewing possible cuts in benefits and payments while the Treasury Department handles cash flow.
All have been mum about their crisis plans, apparently to avoid market speculation or panic.
One analysis, by the Bipartisan Policy Center, suggested that once the government runs out of cash and lacks the power to further borrow, it would need to slash spending at once by as much as a whopping 44 per cent. The U.S. now borrows more than 40 cents for every dollar it spends.
Parks and monuments could be temporarily shut. Clinical trials on new drugs or other scientific research projects as well as half-finished highway construction projects would be put on hold.
The fear is that an extended period in default would throw the already weak U.S. economy back into recession as social services and pension cheques don't go out, civil servants don't get paid and companies that rely on U.S. government contracts and services see their revenues fall.
A recession in the world's largest economy would result in lower tax revenues for the government and a higher deficit, and affect global trade.
Federal Reserve Chairman Ben Bernanke has called the failure to raise the debt limit "a recovery-ending event."
The financial markets' reaction is difficult to gauge. It's not like the U.S. government, with its top-tier credit rating, can't find a willing lender. It's just that Congress has decided not to pay its bills. And leaders of both parties have committed themselves to raising the debt ceiling.
So investors might not view a default as serious. On the other hand, no one knows.
According to an analysis by TD Bank, it's highly likely that the first assets to be affected after a default would be money-market funds that hold government securities, banks that buy bonds directly from the Federal Reserve and resell them to consumers, including pension and mutual funds; and the foreign investor community, which holds nearly half of all Treasury securities.
As well, the currency markets would likely accelerate the selling of the U.S. dollar that has been underway recently, possibly challenging the greenback's status as the world's prime "reserve currency."
China and other countries that now hold about 50 per cent of all U.S. Treasury securities could start dumping them, said TD, further pushing up interest rates and swelling the national debt. It would be a vicious cycle, TD said, of higher and higher interest rates and more and more debt.
Possibly mitigating the rise in rates somewhat would be a move by investors to get out of the currency markets and into assets whose prices are linked to U.S. Treasuries.
But if other central banks sell the U.S. dollar, what would they buy? With the euro zone facing its own debt problems and gold prices already soaring, there are a limited number of places to seek shelter.
The prospect of a slowing economy could drive a selloff in stock markets. That, in turn, would deal a savage blow to already fragile pension plans and similar retirement investments and undermine consumer confidence and the willingness to spend.
The prospect of a slowing economy should mean commodity prices would fall on speculation of lower demand, but that might be mitigated somewhat as traders move into commodities as a tangible store of value.
Will all this happen? No one knows. But JPMorgan Chase CEO Jaime Dimon has questioned why Congress would take the chance.
"No one can possibly say, in my opinion who is semi-rational, could possibly say that there's no chance of a catastrophic outcome. And therefore why would you take that risk?"