New research programmes should delimit their field of enquiry as clearly as possible. First, we need to know more about the origins of the Patron-Client Relationship (PCR) concept: Where does it come from? Subsequently, I will sketch the highly insightful research on PCRs in history, anthropology, ethnology and sociology since the 1950s. These literatures are so far hardly consulted in the PCR publications of International Relations. Second, we should opt for coherent terminology: Which term fits best our phenomenon? I propose to use the term patron-client relations. I will do so when presenting, third, the PCR concept. It should be as clear and parsimonious as possible and well applicable in empirical research. This concept rests on five constitutive properties: relationality, role specificity, reciprocity, asymmetry and durability. It is assumed that these properties can be found in all kinds of PCRs. Fourth, we should strive for a definition of PCRs that is broad enough to capture the rich variety of patron-client relations while at the same time demarcating the concept sufficiently from neighbouring concepts. This definition is presented at the end of this article by synthesizing the five constitutive properties introduced before.
