The grammaticalization of K(case)Ps within Minimalism: formalism vs functionalism, synchrony vs diachrony (pp. 310-325)

Roberts and Roussou (2003) argue that the cross-linguistic distribution of grammaticalization is due to its “simplification”, and the grammaticalization of case-markers displays it since there is a loss of “Agree” relations. Synchronic “simplicity” explains diachronic trends, and formalism and functionalism are not mutually exclusive.