Inflation and CPI: what the numbers measure

What is inflation?

Inflation describes an increase in the general level of prices over a period. In this analysis, it is measured through changes in the consumer price index (CPI), rather than through the price of a single product or a financial asset.

The CPI follows prices of a representative set of household goods and services. It is an aggregate measure: individual prices and an individual household’s spending experience need not move in exactly the same way. INDEC’s CPI explainer provides the general background linked below.

How is the monthly change obtained?

Start with the CPI for the month and the comparable index for the preceding month. Their ratio, expressed as a percentage change, describes how the index moved. This explains the method; it is not a new calculation of any country’s inflation.

RavenInvestor’s country report derives monthly changes from official indices supplied through CEPALSTAT. For Argentina it uses the published national CPI variation from INDEC via ArgentinaDatos. The relevant reference period, geographic coverage and precision must accompany the value; a bare percentage is incomplete.

Monthly, year-on-year and cumulative inflation

A monthly rate compares consecutive months. A year-on-year rate compares a month with the same month a year earlier. A cumulative rate compares the endpoints of the selected window; the window must be specified.

The linked report covers 12 months and displays the same supplied values for its year-on-year and 12-month cumulative columns. It uses index ratios and, for Argentina’s 12-month result, the official year-on-year figure. Its stated alternative is chaining monthly variations. Adding monthly percentage changes is not the declared cumulative method.

An average of monthly rates is a separate statistic. The report’s recent-pace comparison uses three monthly observations against the previous three. That average should not be labeled a three-month accumulated increase.

A slower increase is not the same as a decline

A positive rate still describes a higher index than in the comparison period, even if the rate is smaller than before. A negative monthly change describes a lower aggregate index for that month. It does not establish that every price fell or that the next month will also be negative.

In the country heatmap, the gray class runs from -0.25% to 0.25%. It can contain either sign. The top class starts at 5%, so substantially different readings can share a color. Numerical labels, not color alone, are necessary for interpretation.

What can knowing inflation help with?

It can help describe how a measured consumer-price level has changed, distinguish recent movements from accumulated increases, and frame questions about purchasing power. For a country comparison, use compatible periods and inspect the coverage before interpreting the ranking.

CPI is not an investment return, a currency forecast or an automatic instruction to change a portfolio. The country report measures prices in local currency and does not determine how those prices changed in US dollars. It also does not identify the causes of inflation differences.

Different geographic scopes, rounding, release calendars and later revisions constrain comparisons. A report fingerprint identifies the supplied version; it does not prove that all source observations or methods have been independently audited.

A useful reading order

Check the source and reference month first. Identify whether the number is monthly, year-on-year, cumulative or an average. Then inspect the country coverage, precision and any missing observations. Only after those checks should the color pattern or ranking guide a comparison.

Apply that sequence to the linked analysis: it separates the monthly heatmap, cumulative country ranking and supplied three-month averages. Its historical sample does not guarantee that any of those patterns will recur.

Application and sources

Read the nine-country inflation comparison, with 108 country-month observations, chart, tables and fingerprint. The specific methodology comes from the report dated September 26, 2026, 21:01 UTC.

General indicator background: INDEC: what the consumer price index measures.

Financial information for educational purposes only. This is not personalized financial advice or a recommendation to buy or sell any asset. Historical data does not guarantee future results.