The Ghana Statistical Service (GSS), in collaboration with the Ministry of Food and Agriculture (MoFA), has released three landmark reports that provide the country’s first nationally representative conversion factors for non-standard units of measurement widely used in agriculture and food trade.
The publications, produced under the Non-Standard Units Survey (NSUS), cover measurements used at the household, farmgate and market levels, offering critical data on how commonly used units such as olonka tins, margarine tins, heaps, bundles, cups, bottles and size-based classifications can be converted into standard metric measures.
According to GSS, the reports address a long-standing challenge in Ghana’s agricultural sector, where the same non-standard measurement can represent significantly different quantities depending on the commodity or geographical location.
The Service noted that the absence of reliable conversion factors has affected the consistency and comparability of agricultural statistics, with implications for production estimates, food security assessments, trade statistics and major economic indicators such as Gross Domestic Product (GDP) and the Consumer Price Index (CPI).
The survey established conversion factors using the average weight of sampled non-standard units collected from households, farmgates and markets across the country.
Findings from the Household Report show that non-standard units remain the dominant means of measuring food items in Ghanaian homes, but substantial regional variations exist.
Nationally, a small-sized cup of local rice weighs an average of 0.352 kilogrammes, while a medium-sized cup weighs 0.491 kilogrammes. However, the weight of a small cup of local rice ranges from 0.320 kilogrammes in the Savannah Region to 0.378 kilogrammes in Greater Accra.
Similar differences were observed in other commodities. A small-sized Puna yam weighs an average of 1.043 kilogrammes nationwide, but reaches 1.564 kilogrammes in Bono Region.
For gari, a medium-sized cup averages 0.267 kilogrammes in Bono East Region compared with 0.292 kilogrammes in Eastern Region, highlighting significant location-based differences in commonly used household measures.
The Farmgate Report also uncovered significant inconsistencies in the quantities represented by the same transaction units used by farmers and traders.
For dried yellow maize, the cocoa (jute) sack remains the dominant unit in seven regions. However, its average weight ranges from 131.1 kilogrammes in Greater Accra Region to 198.0 kilogrammes in Bono East Region—a difference of nearly 67 kilogrammes.
The report further showed variations in yams sold by count. Nationally, 100 large yam tubers weigh an average of 362.7 kilogrammes, with the Northern Region recording the highest average weight at 363.3 kilogrammes.
GSS observed that size classifications such as small, medium and large often provide unreliable indicators of actual weight.
On the other hand, container-based units used for products such as oils, including bottles and gallons, were found to exhibit greater consistency because of their fixed capacities.
The Market Report similarly found notable differences in commonly used market measurements across regions.
A medium-sized margarine tin, for example, has a national average weight of 0.276 kilogrammes, but varies from 0.228 kilogrammes in Ahafo Region to 0.346 kilogrammes in Ashanti Region.
Regional disparities were also recorded in the sale of yams. Medium-sized yams weigh an average of 1.772 kilogrammes nationally, with weights ranging from 1.301 kilogrammes in Ashanti Region to 2.042 kilogrammes in Volta Region.
According to GSS, the findings underscore the need for region-specific conversion factors to improve the accuracy of agricultural market data and enhance statistical reporting.
The Statistical Service described the three reports as a major milestone in strengthening Ghana’s agricultural data ecosystem.
By enabling widely used non-standard measurements to be translated accurately into standard units such as kilogrammes and litres, the reports are expected to improve the reliability, comparability and quality of agricultural statistics.
The new conversion factors will support policymakers, researchers, development partners and other data users with stronger evidence for planning, policy formulation, monitoring and decision-making.
Source: businesspostonline
