Characterizing Social Fragmentation over Social Networks: An Axiomatic Approach

This paper develops two axiom-based measures to characterize social fragmentation over social networks: generalized fractionalization and proclivity. Many traditional measures of fragmentation, like ethnolinguistic fractionalization (ELF), are highly sensitive to researchers’ definitions of groups and social categorizations and thus highly susceptible to researcher biases. The measures discussed in this paper do not require researchers to define groups a priori if a social network can be observed or perceived between members of the population. In particular, the paper proposes a series of intuitive axioms that uniquely characterize the suggested measures, thereby providing an intuitive meaning to fairly objective measures over a social network. Furthermore, it is shown that these measures can be used to endogenously define social cleavage structures for any social network. In short, this paper develops intuitive axiomaticallycharacterized measures of social fragmentation which can be derived directly from the structure of a social network without relying upon researcher biases about social categorization.