Nudge is a semantically multifarious concept that originates in Thaler and Sunstein's (2008) popular eponymous book. In one of its senses, it is a policy for redirecting an agent's choices by only slightly altering his choice conditions, in another sense, it is concerned with bounded rationality...

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, we prove a social...

This handbook chapter covers the existing theoretical literature on social preference and social welfare under risk (i.e., when probability values enter the data of the situation) and uncertainty (i.e., when this is not the case and only subjective probability assessments can be formed). Section...