World map of the Big Mac Index for the past 16 years.
The Big Mac index is a term invented by The Economist in 1986 to reflect the difference between purchasing power and exchange rate. For example, the average price of a Big Mac in America in July 2016 was $5.04, while in China it was only $2.79 at market exchange rate. So the Big Mac index says that YUAN was undervalued by 45% at that time.
This map shows the Big Mac indexes of different countries over a span of 16 years. Hover or click on any country to see the details. Move the slider to select a date. The dataset that I used can be downloaded from here.