Judgment Aggregation Theory Can Entail New Social Choice Results

Judgment (or logical) aggregation theory is logically more powerful than social choice theory and has been put to use to recover some classic results of this field. Whether it could also enrich it with genuinely new results is still controversial. To support a positive answer, the authors prove a social choice theorem by using the advanced nonbinary form of judgment aggregation theory developed by Dokow and Holzman (2010c). This application involves aggregating classifications (specifically assignments) instead of preferences, and this focus justifies shifting away from the binary framework of standard judgement aggregation theory to a more general one.