A cost model is developed for the estimation of several technological parameters describing the production process of aluminium smelters worldwide. The model is similar to Baltagi and Griffin's (1988), but, instead of estimating technological change using a panel data set of firms, we estimate, among other things, the vintage effect, using a cross-section of aluminium smelters in operation throughout 1994. The vintage effect is defined as the variable cost differential that may be attributed to the utilization of a specific technical vintage in the production of aluminium in relation to another. Other technological measurements are also discussed: the scale effect or returns to scale and technological characteristic effects, i.e. the variable cost elasticities with respect to pot size and current intensity. The results show that considerable cost reductions may be expected from the change of old technical vintages to more recent ones. Also, results show that for a majority of smelters in the sample, returns to scale seem to be exhausted. Finally, variable costs are very sensitive to pot size in the sense that large cost reductions can be expected from the increase in pot size, an important characteristic of the technology used by smelters.
