I just learned about the GDP deflation index and found this concept quite interesting for understanding the economic situation. Simply put, the GDP deflation index (also called the implicit price deflator) is a way to measure how the prices of all goods and services in a country change over time.

What’s great about it is that it helps you separate whether GDP growth is due to rising prices or due to a genuine increase in production. The GDP deflation index works by comparing nominal GDP (calculated at current prices) with real GDP (calculated at the base year’s prices). The difference between the two is the level of price change.

The calculation formula is also not complicated: the GDP deflation index equals (nominal GDP divided by real GDP) multiplied by 100. Then, if you want to know by how many percent the overall price level has changed, subtract 100 from the result.

It’s also easy to interpret the results. If the GDP deflation index is 100, prices haven’t changed compared with the base year. If it’s greater than 100, prices have increased (inflation). If it’s less than 100, prices have decreased (deflation).

Let me give an example to make it easier to imagine. Suppose that in 2024, a country’s nominal GDP is 1.1 trillion USD and its real GDP (using 2023 as the base) is 1 trillion USD. In that case, the GDP deflation index would be 110. This means the overall price level increased by 10% since 2023. Calculating the GDP deflation index this way helps economists and governments better understand the actual inflation situation in the economy.