If you adjust nominal interest rates by using these measures, or even the dollar itself, which has lost 11% since June, rates are already profoundly negative.

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Therefore, nominal yield is used only for calculating other measures of return.

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In the first three months of this year, Japan's real global exports were 10% lower than during the same period a year earlier, according to Richard Katz of the Oriental Economist Report. (A "real export" measures units shipped, not the yen value.) Nominal exports, measured in yen instead of number of widgets, have not taken such a severe beating.

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