Simultaneous EF1 and approximate MMS allocations for submodular valuations
Pith reviewed 2026-06-27 23:01 UTC · model grok-4.3
The pith
Allocations can be both constant-factor MMS and EF1 for agents with submodular valuations.
A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.
Core claim
We design allocations that simultaneously satisfy ρ-MMS for constant ρ and EF1 (in fact also EFL) when agents have submodular valuations.
What carries the argument
An allocation construction that extends the techniques and constants known to work for additive valuations to the submodular case while preserving both the constant-factor MMS bound and the EF1 property.
If this is right
- Agents with submodular valuations receive allocations that are fair according to both share-based and comparison-based criteria at once.
- The same constant factors established for additive valuations remain valid after the extension.
- Existence holds for arbitrary numbers of agents and items under submodular preferences.
- The result applies equally to the stronger EFL notion in addition to EF1.
Where Pith is reading between the lines
- The same simultaneous guarantees may hold for other valuation classes that lie between additive and submodular.
- If the construction is algorithmic rather than purely existential, it would yield polynomial-time methods for producing the allocations.
- Real-world settings with diminishing marginal returns could adopt the same dual fairness standard without extra computational cost.
Load-bearing premise
The methods and constants that produce simultaneous fairness for additive valuations continue to work when valuations are submodular.
What would settle it
A concrete instance with submodular valuations in which no allocation is both EF1 and ρ-MMS for any fixed constant ρ.
read the original abstract
There are two common classes of fairness notions that are considered when allocating $m$ indivisible items to $n$ agents of equal entitlements. One is that of share-based fairness notions, with the maximin share (MMS) and its relaxations to $\rho$-MMS being prominent representatives of this class. The other is that of comparison-based fairness notions, with envy-freeness (EF) and its relaxations such as EF1 being prominent representatives of this class. In general, no class offers good guarantees for the other class. In this work, we design allocations that simultaneously satisfy notions from both classes, and specifically, are $\rho$-MMS for constant $\rho$ and EF1 (in fact, also EFL). Such results were previously known when agents have additive valuations, and we prove such results for the more general class of submodular valuations.
Editorial analysis
A structured set of objections, weighed in public.
Referee Report
Summary. The manuscript claims to prove the existence of allocations of m indivisible items to n agents with submodular valuations that simultaneously satisfy EF1 (and EFL) and ρ-MMS for some constant ρ independent of n and m. This extends prior results known only for additive valuations by showing that the same combined guarantees hold in the more general submodular setting.
Significance. If the central existence result holds, it meaningfully broadens the applicability of simultaneous share-based and comparison-based fairness guarantees beyond additive valuations, which is a standard strengthening in fair division. The work is credited for targeting a natural generalization and for asserting constructive or existence proofs that preserve constant-factor approximations.
major comments (1)
- [Abstract] Abstract (final paragraph): the claim that additive-case techniques extend to submodular valuations while preserving constant ρ-MMS and EF1 is asserted without any derivation steps, lemmas, key equations, or verification; the provided text supplies no argument supporting that the extension preserves both guarantees simultaneously.
Simulated Author's Rebuttal
We thank the referee for their review. Below we respond to the single major comment.
read point-by-point responses
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Referee: [Abstract] Abstract (final paragraph): the claim that additive-case techniques extend to submodular valuations while preserving constant ρ-MMS and EF1 is asserted without any derivation steps, lemmas, key equations, or verification; the provided text supplies no argument supporting that the extension preserves both guarantees simultaneously.
Authors: Abstracts in theoretical computer science papers are concise summaries of results and contributions; they are not intended to contain derivation steps, lemmas, or full proofs. The manuscript abstract correctly states the main theorem: simultaneous EF1/EFL and constant-ρ MMS allocations exist for submodular valuations, extending the additive case. The actual extension, including the adaptation of techniques and verification that both guarantees are preserved, is established rigorously in the body of the paper via the sequence of definitions, lemmas, and theorems that constitute the proof. We are happy to add a brief high-level pointer sentence to the abstract if the referee finds it helpful for readability. revision: no
Circularity Check
No significant circularity identified
full rationale
The paper is an existence proof extending prior additive-valuation results (cited as previously known) to submodular valuations while preserving constant-factor MMS and EF1. No equations, fitted parameters, self-definitional steps, or load-bearing self-citations appear in the abstract or description. The central claim does not reduce to its inputs by construction; it is a constructive extension with independent content. This matches the default expectation of no circularity (score 0-2).
Axiom & Free-Parameter Ledger
axioms (1)
- domain assumption Valuations are monotone submodular
Reference graph
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