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 opposite. After proving a general impossibility result on judgment aggregation, we construct an embedding of preference aggregation into judgment aggr...

In computational social choice, the complexity of changing the outcome of elections via various control actions, such as adding or deleting candidates or voters, has been studied intensely. We introduce the concept of control for judgment aggregation procedures, and study the complexity of changing the outcome of such procedures via control by adding, deleting, or replacing judges.

Judgment aggregation is concerned with the problem of aggregating individual views on logically related issues. It offers a general framework in which several different types of aggregation problems can be represented and studied. Furthermore, judgment aggregation can be applied to problems that consider together issues that are typically considered as separate aggregation problems. E.g., judgm...

The literature on judgment aggregation has now been moving from studying impossibility results regarding aggregation rules towards studying specific judgment aggregation rules. Here we focus on a family of rules that is the natural counterpart of the family of Condorcetconsistent voting rules: majority-preserving judgment aggregation rules. A judgment aggregation rule is majority-preserving if ...

Judgment aggregation theory, which concerns the translation of individual judgments on logical propositions into consistent group judgments, has shown that group consistency generally cannot be guaranteed if each proposition is treated independently from the others. Developing the right method of abandoning independence is thus a high-priority goal. However, little work has been done in this ar...

A perceived duration is affected by the magnitude of a stimulus. In most studies, the magnitudes are attributed to the target stimulus itself. We focused on a representation of magnitude organized in the brain, using ascending and descending numbers. We investigated whether these representations affected the duration judgment. A subject watched the ascending, descending, or randomly ordered num...

Judgment aggregation is a recent formal discipline that studies how to aggregate individual judgments on logically connected propositions to form collective decisions on the same propositions. Despite the apparent simplicity of the problem, the aggregation of individual judgments can result in an inconsistent outcome. This seriously troubles this research field. Expert panels, legal courts, boa...

When individual judgments (‘yes’ or ‘no’) on some propositions are aggregated into collective judgments, outcomes may be sensitive to the choice of propositions under consideration (the agenda). Such agenda-sensitivity opens the door to manipulation by agenda setters. I define three types of agenda-insensitivity (‘basic’, ‘full’, and ‘focal’) and for each type axiomatically characterize the agg...

Opinion aggregation problems arise when a number of individuals express different opinions on some set of variables (the ‘agenda’) and we wish to combine them into a single consistent ‘collective’ opinion on each variable. General methods for solving problems of this kind have been extensively studied in different domains for instance in social choice theory, in statistics and in judgment aggre...