This paper applies a novel empirical approach to characterising the horizontalness and verticalness of affiliates based on Yeaple’s complex FDI concept. In its simplest form, horizontalness is measured as affiliates' local sales share while their verticalness is measures as their share of non-local sourcing of intermediates. Japanese affiliates in most sectors and nations are partly vertical and partly horizontal but those in North American are far more ‘horizontal’ than those in the EU and Asia. Affiliates became more vertical between 1996 and 2005. A four-way sales and sourcing split (host, home, regional and RoW) suggests that affiliates act as nodes in regional production networks – especially in Asia. We posit several hypotheses that could be tested with our empirical approach.