Government agencies produce indexes that purport to measure international competitiveness. The most common version is the real effective exchange rate, which is some form of weighted average of the real exchange rates of the country's trading partners. Such indexes convey a false sense of...

"Currency values, prices, consumption and incomes are at the heart of the economic performance of all countries. In order to make a meaningful comparison between one economy and another, economists routinely make use of purchasing power parity (PPP) exchange rates, but whilst PPP rates are...