BEGIN:VCALENDAR VERSION:2.0 PRODID:-//132.216.98.100//NONSGML kigkonsult.se iCalcreator 2.20.4// BEGIN:VEVENT UID:20251028T134033EDT-1582Tivne3@132.216.98.100 DTSTAMP:20251028T174033Z DESCRIPTION:'Efficient Learning under Ambiguous Information'\n\nMira Frick (Yale)\n (with Ryota Iijima and Yuhta Ishii)\n November 11\, 2022\, 3:30 t o 5:00 PM\n Leacock 429\n\nHost: Larry Epstein\n Field: Theory\n\nAbstract: \n We provide a systematic approach to compare different belief-updating ru les under ambiguity\, based on analyzing their performance in learning set tings. We consider a decision-maker (DM) with maxmin expected utility pref erences who observes many signals about an unknown state of the world\, an d then solves a decision problem based on her updated beliefs. Capturing s ignal ambiguity\, the DM perceives a set of possible signal structures. A belief-updating rule maps sequences of signals to sets of posteriors about the state\, and the DM chooses optimally based on her worst-case posterio r. We measure the learning efficiency of each updating rule by considering the DM’s induced worst-case expected payoff\, evaluated from an ex-ante p erspective. Thus\, updating rules with higher learning efficiency can be v iewed as displaying less dynamic inconsistency. We provide a simple charac terization of the learning efficiency of each updating rule. This has the following main implications. First\, in stationary environments (i.e.\, wh en signal draws are conditionally i.i.d.)\, we show that learning efficien cy is maximal if (and\, in a sense\, only if) the DM uses maximum-likeliho od updating\; in contrast\, the widely used full-Bayesian updating rule is generically (potentially highly) inefficient. Second\, in non-stationary environments (i.e.\, when signal structures can vary over time)\, we show that learning efficiency is maximal if (and\, in a sense\, only if) the DM uses a maximumlikelihood updating rule that (mis)perceives the environmen t to be stationary.\n DTSTART:20221111T203000Z DTEND:20221111T220000Z LOCATION:Room 429\, Leacock Building\, CA\, QC\, Montreal\, H3A 2T7\, 855 r ue Sherbrooke Ouest SUMMARY:Mira Frick (Yale)\, 'Efficient Learning under Ambiguous Information ' URL:/economics/channels/event/mira-frick-yale-efficien t-learning-under-ambiguous-information-340868 END:VEVENT END:VCALENDAR