Abstract
This article summarizes the main contemporary theoretical approaches to international institutions as well as significant theories of institutions, which build upon those approaches. In line with the existing overviews, I focus on realism, neoliberalism and constructivism.
All three approaches differ in regard to both the origin and impact of institutions. Whereas, the basic realist perspective regards state interests and power to be the main source of the institution's origin; the basic perspective of neoliberalism emphasizes the structure of state interests and collective action problems, which result from it.
Many constructivists presume that so called general institutions determine the origin of specific institutions. According to realists, the impact of institutions is dependent on state interests and power; institutions only regulate state behaviour in a limited way.
The neoliberal conception of institutions infers that: institutions significantly regulate state behaviour since they help states resolve collective action problems. According to constructivists: institutions even constitute state identities and interests.