Are exchange rate models about as accurate as tossing a coin?

After falling a third against the euro over the last three years, the big question is, can the dollar fall much further? If so, can anyone predict when the collapse will end because, according to Alan Greenspan, to his knowledge no model projecting movements in exchange rates is superior to tossing a coin. As a model builder, fortunately I can confirm that at least one set of models did expose the dollar"s over-valuation. In November 2001, I wrote that it was the most overvalued of 29 currencies researched in our Forex RouteMap and predicted that the dollar would be the next bubble to bur...