Desirable Tie-breaking Rules in Collective Decision Making

Judgment aggregation (JA) studies how to aggregate individual judgments to
form collective decisions. Examples are expert panels, legal courts, boards, and
councils. The problems investigated in this new field are relevant and common to
many situations. Nevertheless, the existing procedures are idealized and, likewise
the related problems of preference aggregation in social choice theory, the field is
plagued by impossibility theorems. In this paper, we extend standard JA in order to
offer a more realistic framework and to escape the impossibility results. We propose
to distinguish between abstainers and neutral judgment as well as to model the notion
of confidence a group member may have in the decision rule by assigning to each
criterion a normalized weight. We then show how this new framework may help us
to avoid indecision in most cases.