The Economist’s recently updated Big Mac Index seems to add credence to the views of Mr. Krugman over those of Mr. Roach from this item earlier today, part of an increasingly nasty dispute (at least, for economists) about China’s currency policy.
Does anyone know if there is any empirical data on using the Big Mac Index as the basis for a FOREX trading strategy? It seems pretty simple and, over the long run, would likely be profitable to bet against the overvalued currencies and go long the undervalued ones.