The reverse happens if the economy suffers a negative shock.

ECONOMIST: Assets and their liabilities

Unemployment claims in the U.S. once again provided a negative shock to investors as initial claims shot up to a total of 472K and was one more jab to the dollar.

FORBES: Broad Dollar Weakness Lifts European Currencies

But it is certain, as opposed to merely likely, that the recent oil-price hike is a substantial negative supply shock.

ECONOMIST: Oil and the new economy

Factor in Libya as a negative supply shock (oil).

FORBES: Think of Japan As A Negative Demand Shock

Still others were convinced the economy was already rolling over into its next recession even before the reports this week that consumer confidence plunged in January, and the bigger shock, that GDP growth turned negative in the December quarter, dropping to minus 0.1% compared to the consensus forecast for growth of 1.1%.

FORBES: Usually Right, The Market Says No Problem For Economy In Sight

"We are looking at negative growth for the second quarter, and that will really shock people, " says Kanika Singh of British consultancy IDEA in the Lion City.

CNN: FROM BAD TO WORSE

The problem arises if people start to believe that Treasuries might be risky, say because of a negative report from a ratings agency or some other kind of shock.

FORBES: America's Negative S&P Rating: Premonitions of a Debt Crisis?

The Keynesian story goes like this- if there is collapse in private sector demand due to a failure of business confidence or some other economic shock, then rather than suffer unemployment and all the other negative consequences of recession it is possible for government through public spending to replace the lost demand and steer the economy back to full employment.

FORBES: Shock horror - the Olympics are not Keynesian

So it was a rude shock to Litton and its legions of Wall Street admirers when FORBES ran the first negative story on the seemingly perpetually successful company.

FORBES: Magazine Article

In Thailand's case, the shock occurred in July 1996 when Moody's put Thailand's short-term ratings on Negative Outlook.

CNN: Emotional Indicators

The maintenance of the Aaa with a negative outlook into 2014 is highly unlikely unless the method adopted to achieve debt stabilization involved a large, immediate fiscal shock with a resulting unstable economic situation.

FORBES: Moody's Says U.S. Has Until End Of 2013 To Save AAA Rating