EU, the authors split selected member countries into two groups: the core and the periphery.

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With a common monetary policy, both the core and the periphery are about to get the opposite of what they need.

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But optimists argue that the scale of the bond-market moves and the dynamics behind them are totally different in the core and in the periphery.

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If we were focusing just on the EUR, then the market should be expecting the trend of firmer data in Europe to continue this week, both in the core and in the periphery.

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The fundamental problem that Mr Draghi faces is the acute divergence within the euro zone as capital flight sucks funds out of the periphery and into the core, making monetary conditions simultaneously tight and loose.

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The catastrophe could start in the periphery, but it would spread fast and engulf the core soon enough.

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But in the United States, and much of the rest of the high-income world, this is accomplished by bringing residents from the periphery to the core by car, train, bus and increasingly through telecommunications, even as most jobs are located elsewhere in the urban area.

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Neither has a strong central core, and most of the jobs in the areas are on the periphery.

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There are other strategies that could work, most notably relative deflation, or rather lower inflation in the periphery countries, higher inflation in the core, so that the relative costs and prices come into line but do so in the context of general inflation.

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