TIL in 2011 the Argentine government is believed to have begun making McDonald's underprice the Big Mac specifically to cover the country's high inflation on The Economist's Big Mac index

The Big Mac index started as a joke, but became a somewhat respectable—if still highly informal—way of measuring Purchasing Power Parity. Argentina took advantage of this by making it really cheap but hiding it so no one would order it, artificially improving the country's score.