TITLE:
An Axiomatic Characterization of the Leximin Choice Rule
AUTHORS:
Osamu Mori
KEYWORDS:
The Leximin Choice Rule, The Lorenz Criterion, Suppes-Sen Optimality, The Common Ordinal Invariance Axiom
JOURNAL NAME:
Theoretical Economics Letters,
Vol.9 No.6,
August
30,
2019
ABSTRACT: This study discusses the characterization of the
lexicographic maximin (leximin) choice rule using an axiom related to the
Lorenz criterion, which states that a utility vector that Lorentz dominates a
solution vector should not be Pareto dominated by any feasible vector, named
Pareto Undominatedness of Lorenz-superior Distribution (PULSD). PULSD in itself
does not imply that a solution vector of the choice rule is Lorenz undominated
by any utility vectors in the feasible set.
Therefore, we may say that the PULSD’s requirement for inequality aversion is
weak. Indeed, PULSD is consistent with the utilitarian choice rule, which is
viewed as indifferent to equity. We show that the leximin choice rule is
characterized by PULSD, combined with the Suppes-Sen optimality and the
common ordinal invariance axiom.