Big Mac Index - Overview

Overview

The Big Mac index was introduced in The Economist in September 1986 by Pam Woodall as a semi-humorous illustration and has been published by that paper annually since then. The index also gave rise to the word burgernomics.

UBS Wealth Management Research has expanded the idea of the Big Mac index to include the amount of time that an average worker in a given country must work to earn enough to buy a Big Mac. The working-time based Big Mac index might give a more realistic view of the purchasing power of the average worker, as it takes into account more factors, such as local wages.

One suggested method of predicting exchange rate movements is that the rate between two currencies should naturally adjust so that a sample basket of goods and services should cost the same in both currencies (PPP). In the Big Mac index, the basket in question is a single Big Mac burger as sold by the McDonald's fast food restaurant chain. The Big Mac was chosen because it is available to a common specification in many countries around the world as local McDonald's franchisees at least in theory have significant responsibility for negotiating input prices. For these reasons, the index enables a comparison between many countries' currencies.

The Big Mac PPP exchange rate between two countries is obtained by dividing the price of a Big Mac in one country (in its currency) by the price of a Big Mac in another country (in its currency). This value is then compared with the actual exchange rate; if it is lower, then the first currency is under-valued (according to PPP theory) compared with the second, and conversely, if it is higher, then the first currency is over-valued.

For example, using figures in July 2008:

1. the price of a Big Mac was $3.57 in the United States (varies by store)
2. the price of a Big Mac was £2.29 in the United Kingdom (Britain) (varies by region)
3. the implied purchasing power parity was $1.56 to £1, that is $3.57/£2.29 = 1.56
4. this compares with an actual exchange rate of $2.00 to £1 at the time
5. (2.00-1.56)/1.56 = 28%
6. the pound was thus overvalued against the dollar by 28%

The Eurozone is mixed, as prices differ widely in the EU area. As of April 2009, the Big Mac is trading in Germany at €2.99, which translates into US$3.96, which would imply that the Euro is slightly trading above the PPP, with the difference being 10.9%.