How to Understand Core Inflation — CPI vs Core Inflation

Inflation — Not as Simple as You Think

When media reports "inflation is 4%", they're talking about the CPI indicator. But this is just one way to measure price increases. For a conscious investor, core inflation is equally important — and understanding how they differ.

CPI — Consumer Price Index

What does it measure?

CPI (Consumer Price Index) measures the change in prices of a basket of goods and services purchased by the average household. GUS (Statistics Poland) checks prices of hundreds of products monthly and calculates the average change.

What does the CPI basket contain?

• Food and non-alcoholic beverages (~25% of basket)
• Housing and energy (~20%)
• Transport (~10%)
• Clothing, health, education, entertainment, and others

The problem with CPI

CPI is very sensitive to supply shocks. When oil prices jump 50% or drought destroys crops, CPI shoots up — even if the rest of the economy is stable. This is "noise" that makes it difficult to assess the real inflationary trend.

Core Inflation — Signal Without Noise

What is it?

Core inflation is CPI after excluding the most volatile components — usually food and energy prices. NBP (National Bank of Poland) publishes several measures of core inflation:

• Excluding food and energy prices — most popular
• Excluding administered prices — without state-regulated prices
• 15% trimmed mean — excludes 15% of the most extreme price changes
• Net inflation — after excluding food and fuel

Why is it more important?

Core inflation shows persistent price trends in the economy. If CPI falls because oil became cheaper, it doesn't mean inflationary pressure has disappeared. Core inflation will confirm or deny this.

Practical Example

Imagine this situation:

CPI is falling fast — looks optimistic. But core inflation barely moved. This means the CPI drop is mainly due to cheaper energy or food, while fundamental price pressure remains high.

What This Means for Your Finances

Savings

If your deposit yields 5% and core inflation is 4.5% — your real profit is only 0.5%. Look at core inflation, not headline inflation, when evaluating real returns.

Interest Rates

RPP (Monetary Policy Council) looks at core inflation when deciding on rates. Even if CPI falls, with persistent core inflation, rates may remain high — affecting loans, bonds, and the real estate market.

Investments

• Inflation-indexed bonds (COI, EDO) protect against CPI — but CPI and core inflation can diverge
• Stocks — in the long term, companies pass costs to consumers, protecting against inflation
• Real estate — rents usually rise with core inflation

Where to Check Data?

• GUS (stat.gov.pl) — monthly CPI inflation report
• NBP (nbp.pl) — core inflation measures, published with 2-week delay
• Trading Economics — historical charts and international comparisons

How Freenance Can Help

Freenance considers inflation when calculating your financial goals and Financial Freedom Runway. You see how the real value of your savings changes over time and whether your investments actually beat inflation — not nominally, but in real terms.

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