A number of past studies of South African agricultural production and productivity performance used a hybrid Törnqvist-Theil approach to forming output aggregates based on a series of Laspeyres-type aggregations of sub-sectoral outputs rather than using the underlying commodity-specific price and quantity data directly. As a result, the studies suffer index number bias and a number of shortcomings that are due to the underlying price and quantity data. These shortcomings include inconsistencies over time in the inclusion of production originating from homeland farmers as well as changing statistical methods and definitions used in forming the national estimates of agricultural production. By addressing these data and measurement issues, including the use of the Fisher Ideal indexing methods, we generate an output quantity index that differs substantially from those presented in past studies. For example, the hybrid Törnqvist-Theil approach suggests that South African agricultural output grew by an average of 2.96 per cent per year over the century spanning 1910-2010, whereas a Fisher Ideal aggregation of the same underlying price and quantity data suggests a growth rate of 3.33 per cent per year.
Bibliographical noteFunding Information:
The research supporting this paper was funded principally by the South African Department of Agriculture, Forestry and Fisheries (DAFF) and the Agricultural Research Council (ARC), with additional support from the University of Minnesota’s International Science and Technology Practice and Policy (InSTePP) centre, the International Food Policy Research Institute, the University of Pretoria, and the Bill and Melinda Gates Foundation by way of the HarvestChoice project. The authors thank the staff at the Directorate: Agricultural Statistics for their excellent assistance in the revision of the underlying data. They also thank the librarians at the DAFF and ARC for outstanding support in tracking down sometimes obscure sources of data and information.
© 2016 Agricultural Economics Association of South Africa.
- Divisia indexes
- agricultural production