"If you have a moment of instability, what happens is the muscles counteract by working to create stability -- in theory, " he said.

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The stability pact that in theory limits budget deficits may buckle.

ECONOMIST: Financial markets and the euro

Sanctions exist, in theory, in the stability and growth pact, which requires euro-area countries to keep deficits below 3% of GDP and government debt below 60% of GDP, but they have never been imposed.

ECONOMIST: Charlemagne

In theory, a discretionary central bank could limit the quantity of money and achieve long-run price stability by controlling the growth of nominal final demand.

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The theory is that as your retirement date arrives, the changing asset mix will provide the proper recipe for stability and growth.

FORBES: Connect