Inflation: why one number is not enough

Explainer · Editorial draft

The Consumer Price Index summarises changes in the cost of a consumer basket. Individual products affect it differently: both the price change and the product’s weight in the basket matter.

What to compare

A month-on-month change measures movement from the previous month. A year-on-year change compares prices with the same month a year earlier. They answer different questions.

Separating trends from shocks

To assess how broadly prices are rising, researchers can examine the distribution of price changes and trimmed means. These calculations require detailed price indices and matching weights. Results should be checked by reconstructing the aggregate index.

Primary sources for further verification

State Statistics Service of Ukraine · National Bank of Ukraine