Ghana’s official statistician, the Ghana Statistical Service (GSS), has launched national conversion factors to standardise traditional food measurements. This follows a nationwide survey revealing inconsistencies in units like 'olonka', cups, and buckets across markets. The new measures aim to improve the accuracy of crucial economic data.
The inaugural Non-Standard Units Survey provided the first comprehensive evidence of how local measurement units differ significantly. These variations depend on location, commodity type, and local market practices. For consumers, this problem makes it difficult to compare prices and ensure they receive fair value for money. For policymakers, it complicates the measurement of inflation and agricultural production.
This initiative fits into Ghana's broader economic management efforts to ensure data accuracy. Although Ghana adopted the metric system in 1975, non-standard units remain widely used in food markets. The GSS stated that the survey's purpose is to improve the conversion of local food measurement units into standard kilograms and litres. This will allow official statistics to better reflect actual trade and consumption nationwide.
The GSS survey showed that familiarity with traditional units does not mean consistency. Identical containers, such as cups or buckets, hold different quantities based on the market and the commodity. These differences distort price comparisons across regions. They also make it hard to determine whether food is truly cheaper in one market than another.
This issue is particularly critical for the Consumer Price Index (CPI), which tracks price changes. If the underlying quantity being priced varies, price data may not fully capture the real cost movement. This challenge also affects agricultural statistics. Farm output and household consumption are often reported in local units before conversion. Inaccurate conversion factors weaken estimates for production, consumption, poverty, and food security.
The Non-Standard Units Survey is more than a technical exercise. It bridges the gap between traditional market practices and standard measurement systems necessary for modern economic management. The survey found wide variations in solid food commodities weighed using local units. Liquid commodities, such as palm oil, showed greater consistency due to more uniform container-based measurements.
The Ghana Statistical Service's new national conversion factors will translate common local measures into standard units. These factors will improve the accuracy of the CPI, agricultural production statistics, poverty analysis, household expenditure surveys, and food security assessments. Accurate conversions mean consumers can better understand what they are paying for. Traders, analysts, and policymakers can also compare prices across markets more reliably.
This standardisation is vital as food prices significantly drive cost-of-living pressures and public concern. The Bank of Ghana will benefit from more precise food price data, strengthening inflation analysis and monetary policy decisions. The Ministry of Finance and other agencies can improve fiscal planning, social protection targeting, and poverty assessments. For the Ministry of Food and Agriculture, standardised conversion factors support reliable agricultural production estimates and food supply planning. This survey was a collaboration between the GSS and the Ministry of Food and Agriculture, with technical support from the 50x2030 Initiative.