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UID:event-11466@www.amse-aixmarseille.fr
DTSTAMP:20260421T214109Z
CREATED:20260421T214109Z
LAST-MODIFIED:20260421T214109Z
STATUS:CONFIRMED
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SUMMARY:Economic theory seminar - Marcus Pivato
DTSTART:20250328T110000Z
DTEND:20250328T120000Z
DESCRIPTION:When a group confronts a decision involving uncertainty\, diffe
 rent individuals may have different (probabilistic) beliefs about the world
 . In order for the group to make rational decisions (i.e. to maximize subje
 ctive expected utility)\, we must construct probabilistic beliefs for the g
 roup as a whole. Probabilistic belief aggregation rules (also called opi
 nion pooling rules) are functions that "aggregate" the individuals' dispar
 ate beliefs into a single collective belief. An important class of such rul
 es are the geometric (or logarithmic) aggregation rules\, in which the c
 ollective belief is a (renormalized) geometric average of the individuals' 
 beliefs. These rules have many nice properties\, but they have three major 
 shortcomings:1. Existing definitions of geometric aggregation for uncountab
 ly infinite spaces involve a major domain restriction: they assume that all
  probabilities are absolutely continuous with respect to a common "referenc
 e measure".2. Geometric aggregation is only well-defined for profiles that 
 are coherent\, meaning that the beliefs of the agents have overlapping sup
 port.3. In many decision problems\, agents do not have a clear idea of the 
 space of possible "states of nature"\; they only have in mind some set of s
 tatements (each of which could be either true or false). Formally\, their b
 eliefs take the form of a probability measure defined on an abstract Boole
 an algebra. But geometric aggregation is not well-defined for these kinds o
 f beliefs.In this presentation\, I will discuss an extended version of geom
 etric aggregation that solves all three problems.\\n\\nContact: Jiakun Zhen
 g : jiakun.zheng[at]univ-amu.fr\n\nPlus d'informations: https://www.amse-a
 ixmarseille.fr/fr/evenements/marcus-pivato
LOCATION:Îlot Bernard du Bois - Salle 15\, AMU - AMSE\, 5-9 boulevard Maur
 ice Bourdet\, 13001 Marseille
URL;VALUE=URI:https://www.amse-aixmarseille.fr/fr/evenements/marcus-pivato
CONTACT:Jiakun Zheng :&nbsp\;jiakun.zheng[at]univ-amu.fr
TRANSP:OPAQUE
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