The countdown to the U.S. government brush with debt ceiling this week is the top economic news -- not just in American markets, but all over the world.

Thursday, Oct. 17, is the day that Jack Lew has said he will run out of room under the debt ceiling.

Contrary to popular belief, it does not mean that the U.S. will default on its debt on Thursday if Congress doesn’t raise the debt limit before then. Instead, Oct. 17 is when Lew anticipates being unable to issue new debt.

Since May, when the public debt hit the $16.7 trillion ceiling, Lew has been freeing up headroom under the debt ceiling to issue new debt by moving around government accounts. Thursday is the day that he thinks that all the steps available to him will have been taken, and the only resources at his disposal will be incoming tax revenues and roughly $30 billion in cash on hand.

In other words, Thursday is that last day that Lew can guarantee he will be able to make all of the government’s obligated payments in full and on time.

What happens after that is uncertain.

How that uncertainty plays out in the markets will be something the White House and Capitol Hill will be following throughout the week. Bond markets will be closed Monday for Columbus Day, but stock markets and foreign markets will be open. U.S. and world futures fell Sunday night and Monday morning.

If markets start to crash and financial stress increases, that will put pressure on lawmakers to cut a deal over raising the debt ceiling, in much the same way the market panic in the fall of 2008 led to the passage of the TARP bailout, a deeply unpopular measure.

A failure to make a payment on U.S. Treasury debt or uproar over the Treasury missing other payments would be such a momentous event that other economic news will be on the back burner this week.

That's true even though the partial government shutdown is entering a third week, and President Obama nominated a candidate for the Federal Reserve chair, Janet Yellen, last week.

The outgoing chairman, Ben Bernanke, will give a speech Monday night in Mexico City at an event sponsored by Mexico’s central bank.

Major economic reports on inflation, housing starts, and industrial production were scheduled for this week, but will likely be delayed because of the government shutdown.

The Nobel Prize in economics — technically the Sveriges Riksbank Prize in Economic Sciences in Memory of Alfred Nobel — was also due to be announced early Monday morning.