This is certain to be tumultuous, because imposing a single exchange rate across the entire country will bring overnight price drops in some places and huge rises in others.

ECONOMIST: Zaire

His own reforms, such as introducing a simplified, single-rate foreign-exchange mechanism, private banks and mobile phones, remain on the drawing-board.

ECONOMIST: Syria

There is even a precedent: Italy imposed a small tax on all deposits in 1992 as part of its battle to stay in the European Exchange Rate Mechanism, a precursor to the single currency.

WSJ: Euro Zone Moving Into Twilight Zone

The convergence in yields reflects mainly the removal of exchange-rate risk since the creation of the single currency, but that still leaves default risk.

ECONOMIST: World economy

On a constant-exchange-rate basis, an expected high-single-digit percentage increase in worldwide net sales includes sales growth in all regions, ranging from a mid-teens percentage increase in Asia-Pacific to a low-single-digit increase in Japan.

FORBES: Tiffany & Co. Q4 Sales Up 4%

EU's exchange-rate mechanism for at least two years before acceding to the single currency.

ECONOMIST: The single currency

The single currency has deprived its members of any independent control over monetary policy or the exchange rate, so the burden of any necessary response to a recession falls more on fiscal policy.

ECONOMIST: Europe's single-currency rules

Anglo-Saxon sceptics about Europe's single currency gleefully predict that these strains will blow the euro apart, just as they did the exchange-rate mechanism in the early 1990s.

ECONOMIST: The euro