The mainstream GPE theories such as Realism (Economic Nationalism), Liberalism and Historical Structuralism (Marxism) provide a relatively clear analytical distinction while also covering a variety of sub-theories and hybrid paradigms in themselves or at times intersecting with one another in relation to the criticisms around the mainstream theories. This widely recognized analytical classification of the GPE theories owes to Cohn (2011). For the sake of clarity in relation to FDI, however, this section will not indulge in detailed definitions around these rather well-known GPE theories but instead will directly present an overview of more specific FDI theories that relate to the practice of FDI in an attempt to link the existing theoretical approaches with the practice for the better.
Prior to presentation of an overview of FDI theories, still, it is also important to present the internationally recognized definition of FDI. There are basically three internationally accepted definitions of FDI; one belongs to IMF (1993), the second one belongs to OECD (1996), and the third one is that of UNCTAD (2003). For the purposes of this chapter the OECD definition of FDI is taken into account which reads as below: