The Ghana Statistical Service (GSS) has made publicly available, the CPI Technical Methodology Manual to help citizens understand how the Consumer Price Index (CPI) is computed.
The technical manual, according to the Government Statistician, Prof Samuel Kobina Annim, “is a reference tool for anyone who wishes to understand how CPI and associated inflation statistics are calculated”.
It covers the concepts underpinning the index, the methodology used, price data collection and validation, calculation of weights and publication and usage of the different indices.
The 2020 version is available on the GSS website.
Calculating CPI
The Combined Consumer Price Index measures the change over time in the general price level of goods and services that households acquire for the purpose of consumption.
It measures changes in the price of a fixed basket of goods and services purchased by households.
The assumption is that the basket is purchased each month, hence as price changes each month, the total price of the basket will also change.
The rate of inflation is the relative change in CPI between periods.
Current CPI and inflation rate
CPI for September 2020 is 119.8 relative to 120.0 in August 2020.
The year-on-year inflation rate as measured by the CPI was 10.4 percent in September 2020, which is 0.1 percentage points lower than August 2020.
This rate of inflation for September 2020 is the percentage change in the CPI over the twelve-month period, from September 2019 to September 2020.
The monthly change rate for September 2020 is -0.2 percent.
