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The FT's newly ordained "person of the year", the ever sardonically smiling ECB president, Mario Draghi, recently addressed Germany's co-operative banks: eurozone trade, he claimed, accounted for a staggering 40% of Germany's entire GDP. Not a single eyebrow was raised in the audience. The truth is somewhat different: total exports are equivalent to around 43% of Germany's GDP and the eurozone accounts for less than 37% of total exports, according to recently revised figures. That means that exports to the eurozone nominally account for roughly 15% of German GDP. This share will fall further. In reality, however, the contribution of the eurozone to the German economy is even smaller. The reason for this is simple: the eurozone countries do not pay for most imports from Germany;...