Use McDonald's Big Mac meals prices from countries around the world to explore the purchasing power parity of currencies and the food price in each country. Meanwhile, to eliminate exchange rate differences, we will uniformly use the United States dollar (USD) as the currency unit. Obviously, we can find that McDonald's prices in Europe are generally higher than in other regions and continents.
The Food Products inflation index is relatively stable with only minor volatility before September 2021 but the stable pattern is broken after the time point. The inflation index increases sharply from 102.7 to 109.9 with a peak of 110.5. In addition, until September 2021, the inflation rate is elastic and can be adjusted immediately. After that, it immediately pulls back and decreases for a period of time indicating there was a long-term periodic fluctuations. However, after September 2021, inflation increases to a new high level.