Note 27 — Chapter III · THE THEORY OF MONEY AND OF THE FOREIGN EXCHANGES
Reading edition
“Our calculation of the purchasing power parity rests strictly on the proviso that the rise in prices in the countries concerned has affected all commodities in a like degree. If that proviso is not fulfilled, then the actual exchange rate may deviate from the calculated purchasing power parity.” Cassel, Money and Foreign Exchange after 1914, p. 154.