Big Mac Index Misstates PPP at 40, Tracking Labor Costs Instead

Q: Does a $7.99 Big Mac reflect true currency value, or merely the invisible local costs of commercial rent and labor?

A $7.99 Big Mac is not a pure reading of a currency’s “true” value. It is better understood as a rough signal that mixes exchange rates with local costs such as wages, commercial rent, taxes, utilities, advertising and competition. That is the central limitation of the Big Mac Index. It was designed as a simple illustration of purchasing power parity, but a Big Mac is not a globally identical traded good. McDonald’s adapts the burger by market: ingredients, calories, weight, salt content and even the protein can vary. In India, for example, the comparison uses a chicken burger rather than beef. In the UK and Ireland, McDonald’s says it uses local beef. Those differences weaken the idea that the index measures one perfectly standardized product. Even so, the product variations usually do not overturn the broad message. In most countries, adjusting for calories or protein changes the result only modestly. A few markets, such as Mexico and Spain, can look different depending on whether you compare price alone or price per calorie. Israel is a larger outlier because kosher rules materially affect costs. So when Switzerland shows a $7.99 Big Mac against roughly $5.79 in the United States, it does suggest a very expensive economy and a strong franc. But it also reflects Switzerland’s high labor and property costs. The burger price is therefore a useful shorthand for relative price levels and possible currency overvaluation, not a precise measure of intrinsic currency value.

3 articles · Updated · Financial Times · Aug 3

Forty years after its launch, the Big Mac Index is better read as a gauge of labor costs and commercial rents than as a pure purchasing power parity measure.
McDonald’s burgers are not truly identical across markets: recipes, weight, calories and sourcing vary, and restaurant meals behave more like local services than globally traded goods.
Those product differences usually do not overturn the currency signal—only Mexico and Spain flip between overvaluation and undervaluation depending on how the burger is measured.
That helps explain why the index still loosely tracks exchange-rate distortions, while outliers such as the Japanese yen and South Korean won may reflect local labor and city-center rent costs.