Documentation

Linglib.Phenomena.Gradability.Studies.DAmbrosioHedden2024

@cite{dambrosio-hedden-2024} #

D'Ambrosio, J. & Hedden, B. (2024). Multidimensional Adjectives. Australasian Journal of Philosophy 102(2): 253–277. DOI: 10.1080/00048402.2023.2277923

Key Claims #

  1. Multidimensional adjectives require explicit aggregation functions mapping dimensional assessments to overall assessments (§3).

  2. Arrow's impossibility theorem (adapted): under constraints ONC + WO + U + P + I + D, no aggregation function exists for ≥3 dimensions and ≥3 objects. Multidimensional adjectives would be incoherent (§4.1).

  3. Escape routes determine aggregation type (§4.2–4.3):

    • Reject WO (transitivity) → Majority Rule (May 1952)
    • Reject WO (completeness) → Strong Pareto Rule (Weymark 1984)
    • Reject ONC, accept IUC → Utilitarian / weighted sum (Sen 1970)
    • Reject ONC, accept RNC → Cobb-Douglas / weighted product (Tsui-Weymark 1997)
  4. Multiple admissible aggregation functions → comparative vagueness, a source of vagueness specific to multidimensionality (§4.3).

Formalization #

Arrow's constraints on dimensional aggregation (§4, adapted from social choice theory).

  • unrestrictedDomain : Bool

    (U) Defined for all logically possible value profiles.

  • weakOrdering : Bool

    (WO) Output is a weak ordering (reflexive, transitive, complete).

  • weakPareto : Bool

    (P) Unanimous dimensional ranking → same overall ranking.

  • independence : Bool

    (I) Overall ranking of x vs y depends only on their dim values.

  • nonDictatorship : Bool

    (D) No single dimension dictates the overall ranking.

  • ordinalNonComparability : Bool

    (ONC) Only ordinal info used (invariant under monotone transforms).

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      The full Arrovian constraint set (§4.1).

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        fullArrow enables all six constraints. Arrow's impossibility theorem (adapted, §4.1) says these are jointly unsatisfiable for ≥3 dimensions and ≥3 objects — at least one must be abandoned, and each escape route yields a different aggregation type.

        This theorem only records the constraint specification; the impossibility proof itself would require formalizing aggregation over orderings and is not attempted here.

        The adjective athletic has three dimensions: speed (F₁), agility (F₂), and endurance (F₃) (§3). We model two people and show how different aggregation mechanisms yield different verdicts.

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          Dimensional profiles for athletic:

          • Alice: fast, agile, not enduring
          • Bob: not fast, not agile, enduring
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            Under speed-heavy weights [3, 1, 1] with θ = 3, Alice IS athletic (score = 3 + 1 + 0 = 4 ≥ 3) but Bob is NOT (score = 0 + 0 + 1 = 1).

            Under endurance-heavy weights [1, 1, 3] with θ = 3, Alice is NOT athletic (score = 1 + 1 + 0 = 2 < 3) but Bob IS (0 + 0 + 3 = 3 ≥ 3).

            When multiple weight vectors are admissible, the comparative form "x is more athletic than y" is vague: different admissible aggregation functions rank the entities differently.

            This is D&H's central prediction (§4.3): multidimensionality
            generates comparative vagueness through admissibility multiplicity. 
            

            @cite{sassoon-2013}'s framework classifies binding as conjunctive (∀), disjunctive (∃), or mixed (dimension counting). D&H show all three are counting aggregation — a single escape route from Arrow's theorem. Utilitarian aggregation (weighted sum) is a genuinely different mechanism that Sassoon's typology misses.

            Utilitarian aggregation is NOT counting — it is a categorically different escape route from Arrow's impossibility.

            healthy under conjunctive binding: must satisfy ALL dimensions. A person healthy on musculoskeletal and cardiovascular but with disease present is NOT healthy.

            But under counting with k = 2, the same person IS healthy (passes on 2 of 3 dimensions). Counting and conjunctive diverge.