A guide to African currencies: the Milk Index

In 1986 The Economist magazine famously created its Big Mac Index, a guide to the fair value of a currency based on the principle of purchasing-power parity, which states that exchange rates should adjust to bring prices of identical goods into line across national boundaries.

But Big Macs are not sold everywhere. Seeking a similar mechanism applicable to countries in Africa, we have created our Milk Index, based on the price of a gallon of milk.