The Ghana Statistical Service (GSS) is moving to improve the way food is measured and priced across the country after a nationwide survey revealed major inconsistencies in the use of traditional market measures such as olonka, cups, buckets, bundles and heaps.
The findings, published in the inaugural Non-Standard Units Survey, show that the same market container or local measuring unit can represent different quantities depending on the market, region, commodity and even how the container is filled.
According to the GSS, these variations have long made it difficult to accurately compare food prices, monitor inflation and compile reliable agricultural and household consumption statistics.
Although Ghana officially adopted the metric system in 1975, traders and consumers still rely heavily on traditional market measures because they are widely accepted and deeply rooted in everyday trading practices.
However, the survey found that these familiar units are far from uniform.
For instance, an olonka or cup used to measure maize in one market may contain a different quantity from the same measure used elsewhere. Similar inconsistencies were observed with buckets, margarine tins, heaps and bundles, making it difficult for consumers to determine whether they are receiving the same value for the price they pay.
The GSS said these differences also affect the accuracy of the Consumer Price Index (CPI), which is used to track inflation.
When the quantity of a product differs from one market to another, price movements may not fully reflect the actual cost of living faced by households.
The challenge extends beyond inflation. Agricultural production figures, household expenditure data, poverty estimates and food security assessments also rely on converting local market measures into standard units such as kilograms and litres.
Without accurate conversion factors, those estimates can become less reliable.
To address the problem, the Ghana Statistical Service has developed national conversion factors that translate commonly used local market measures into standard metric units.
The agency believes the new system will improve the quality of official statistics while making it easier to compare food prices across different markets.
The survey found that measurements for solid food commodities varied significantly, while liquid products such as palm oil showed greater consistency because traders generally use standard containers.
According to the GSS, the new conversion factors will strengthen inflation measurement, improve agricultural production statistics, enhance household expenditure surveys and support better food security analysis.
More accurate food price data is also expected to support policy decisions by the Bank of Ghana, the Ministry of Finance and the Ministry of Food and Agriculture, particularly in areas such as inflation management, agricultural planning, poverty reduction and social protection.
The survey was conducted by the Ghana Statistical Service in collaboration with the Ministry of Food and Agriculture, with support from the 50×2030 Initiative, a partnership involving the World Bank, the Food and Agriculture Organization and the International Fund for Agricultural Development.
Rather than replacing traditional market practices, the initiative seeks to ensure that commonly used measures such as the olonka, cup, heap and bundle can be accurately converted into standard units for statistical purposes.
The GSS says this will produce more reliable national data while preserving the market practices that many traders and consumers continue to depend on.
With food prices remaining a major concern for households, the agency believes better measurement will contribute to fairer price comparisons, stronger economic analysis and more informed policymaking.
