Can’t weight anymore! South Africa’s use of national accounts and point of sale data to update the CPI basket and weights

Funding constraints and COVID-19 lockdowns prevented Statistics South Africa (Stats SA) from surveying household expenditure data in time for a five yearly update of the consumer price index (CPI) basket and weights. This despite the importance of a relevant CPI for economic policy and the urgency of updated poverty information. In 2022, Stats SA instead used recently benchmarked national accounts estimates together with detailed sales data provided by retailers to update the weights and basket. The paper explains the technical methods used to determine changes to the basket and weights and highlights the importance of user consultations during the project. An assessment of the results lays the methodological groundwork for future weight updates. Key features of the update included using a pre-COVID year as the weights reference period, abandoning price updating and an uneven focus on retail goods at the expense of services.