It is important to test the relevance of supply conditions — relative to demand or neutral conditions — for export-oriented investment (EOI). If supply-side factors are not more pertinent, costly measures in place to attract EOI to South Africa might have unintended consequences. Test results suggest supply-side variables are more important for foreign export-oriented investment and not more important for domestic export-oriented investment, but severe data constraints force the construction of crude EOI proxies for the tests. These constraints expose the need for better EOI information and research.