This paper examines the effect of foreign direct investment (FDI) on growth by focusing on the complementarities between FDI inflows and financial markets. In our earlier work, we found that FDI is beneficial for growth only if the host country has well-developed financial institutions. In this paper, we investigate whether this effect operates through factor accumulation and/or improvements in total factor productivity (TFP). Factor accumulation – physical and human capital – does not seem to be the main channel through which countries benefit from FDI.