What Is a Conflict of Interest ?

It is often pointed out that conflicts of interest are - or should be - of great importance in social science. However, it seems to be far from clear what a conflict of interest is. The main purpose of this paper is to present a preliminary but fairly systematic survey of dif ferent interpretations or definitions of 'conflict of interest'. Intra-party conflicts are not discussed. As a point of departure it is assumed that there is a conflict of interest between two parties if, and only if, their interests are incompatible. The problematic terms here are 'interest' and 'incompatible'. These are very seldom defined in social science. The meaning of 'interest' is discussed in sections 3 and 4; subjectivistic, objectivistic, naturalistic, and normative interpretations of this term are distinguished and exemplified. The meaning of 'incompatible' is discussed in section 5. It is sometimes held that conflict theorists tend to neglect 'real' conflicts of interest. The content of this claim is discussed in the last section.