Phosphate products and the extent of the geographic market

The manufacture and distribution of phosphate rock and its associated products are large consumers of energy. As a consequence, a change in the price of energy can have a quite substantial effect on the cost of production. This will affect the price that the product can be sold for. Whether this will affect the sales of the product is dependent on what is the relevant market. Consequently, to understand this issue, the extent of the geographic market must be defined. To this end, a definition is detailed relying on the concept of instantaneous causality. Monthly data for four phosphate products for the period 1980 through 1985 are used to implement the approach empirically. For three of the four products considered, the empirical results suggest that there is a world market.