Objective rationality foundations for (dynamic) α-MEU

A-Tier
Journal: Journal of Economic Theory
Year: 2022
Volume: 200
Issue: C

Authors (3)

Frick, Mira (not in RePEc) Iijima, Ryota (not in RePEc) Le Yaouanq, Yves (Centre de Recherche en Économi...)

Score contribution per author:

1.341 = (α=2.01 / 3 authors) × 2.0x A-tier

α: calibrated so average coauthorship-adjusted count equals average raw count

Abstract

We show how incorporating Gilboa et al.'s (2010) notion of objective rationality into the α-MEU model of choice under ambiguity can overcome several challenges faced by the baseline model without objective rationality. The decision-maker (DM) has a subjectively rational preference ≿∧, which captures the complete ranking over acts the DM expresses when forced to make a choice; in addition, we endow the DM with a (possibly incomplete) objectively rational preference ≿⁎, which captures the rankings the DM deems uncontroversial. Under the objectively founded α-MEU model, ≿∧ has an α-MEU representation and ≿⁎ has a unanimity representation à la Bewley (2002), where both representations feature the same utility index and set of beliefs. While the axiomatic foundations of the baseline α-MEU model are still not fully understood, we provide a simple characterization of its objectively founded counterpart. Moreover, in contrast with the baseline model, the model parameters are uniquely identified. Finally, we provide axiomatic foundations for prior-by-prior Bayesian updating of the objectively founded α-MEU model, while we show that, for the baseline model, standard updating rules can be ill-defined.

Technical Details

RePEc Handle
repec:eee:jetheo:v:200:y:2022:i:c:s0022053121002118
Journal Field
Theory
Author Count
3
Added to Database
2026-01-25