Where post-GDP, a socio-ecological substitute of GDP, has become increasingly salient within international relations, its practice at an institutional economic level remains largely marginalised. At a discursive level, however, both GDP and post-GDP appear to be both supplementary and antithetical to one another. This thesis investigates this relationship between GDP and post-GDP discourse, as well as the dependency of economic institutions to exercise such a discourse. Constructivist institutionalism initially frames these economic ideas as both constitutive and antagonistic towards institutional stability. This thesis, however, draws primarily upon institutional poststructuralism, articulating GDP/post-GDP discourse, not the agent, as a mechanism that produces economic knowledge and, by association, the institutions that are shaped by it. A two-part analysis takes place, consisting of an historical genealogy of GDP/post-GDP and a discourse logics analysis between the IMF development committee and the economic departments of India and surrounding countries. The findings show that the formative discourse of GDP and post-GDP had become divorced during the 20th century and that while GDP logics often struggle to reconcile requisite development outcomes, economic institutions exercise the two as a unitary discourse; albeit one that maintains a GDP centre.