The relationship between foreign direct investment (FDI) and internati
onal trade is examined with specific reference to US FDI in the UK. Fo
ur complementary hypotheses are tested on a cross-section of UK indust
ries. There is evidence of US FDI being located in UK industries which
have a revealed comparative advantage and that large market size effe
cts are important. On the other hand, little evidence was found for th
e protection jumping and industrial concentration hypotheses.