This introduces the symposium on judgment aggregation. The theory of judgment ag­gregation asks how several individuals' judgments on some logically connected propositions can be aggregated into consistent collective judgments. The aim of this intro­duction is to show how ideas from the...

While a large social-choice-theoretic literature discusses the aggregation of individual judgments into collective ones, there is relatively little formal work on the transformation of individual judgments in group deliberation. I develop a model of judgment transformation and prove a baseline...

While a large social-choice-theoretic literature discusses the aggregation of individual judgments into collective ones, there is relatively little formal work on the transformation of individual judgments in group deliberation. I develop a model of judgment transformation and prove a baseline...

In response to recent work on the aggregation of individual judgments on logically connected propositions into collective judgments, it is often asked whether judgment aggregation is a special case of Arrowian preference aggregation. We argue the op- posite. After proving a general impossibility...

In the theory of judgment aggregation on logically connected propositions, an important question remains open: Which aggregation rules are manipulable and which are strategy-proof? We define manipulability and strategy-proofness in judgment aggregation, characterize all strategy-proof...