Reliability-based preference dynamics: lexicographic upgrade

This article models collective decision making scenarios by using a priority-based aggregation procedure, the so-called lexicographic method, to represent a form of reliability-based ‘deliberation’. More precisely, it considers agents with a preference ordering over a set of objects and a reliability ordering over the agents themselves, providing a logical framework describing the way in which the public and simultaneous announcement of the individual preferences leads to individual preference upgrade. The main results are the definitions of this lexicographic upgrade for diverse types of reliability relations (in particular, the preorder and total preorder cases), a sound and complete axiom system for a language describing the effects of such upgrades, and the definitions for non-public variations.