Polynomial-time construction with subquadratic envy-free subsidies
LLM status Open unverified
D63 — Equity, Justice, Inequality, and Other Normative Criteria and Measurement Economics catalogue openaigpt 6 astra progpt 6 astra ultra 20% cataloguednot recordedOpenStatement
ECON-006 | U | Source passage unverified; not certified as a published open question
Definitions and formal target
Use normalized monotone goods valuations with $v_i(\varnothing)=0$ and $0\leq v_i(S\cup\{g\})-v_i(S)\leq1$ for every $S\subseteq M$ and $g\notin S$. A value oracle returns $v_i(S)$ on request. Returned rational values have at most $L$ bits. The output is a complete partition $A$ and nonnegative rational subsidies $p$.
Find whether an algorithm can guarantee, on every instance, \[ v_i(A_i)+p_i\geq v_i(A_j)+p_j\quad\forall i,j, \qquad \sum_i p_i\leq C n^{3/2}\sqrt{\log(4n)}, \] using $\operatorname{poly}(n,|M|,L)$ oracle calls and bit operations, for an absolute constant $C$.
Clarifications and required assumptions
An instance comprises $n,m$, exact value-oracle access to $n$ normalized monotone set functions, and an upper bound $L$ on the binary encoding length of every returned rational. Represent a queried bundle by its $m$-bit incidence vector. Exact envy inequalities are checked against exact oracle values. The claimed running time includes the size of the output subsidies. Here the displayed rate is the target being asked for; its attribution as an already proved existence rate could not be checked. The logarithm is natural; another fixed logarithm base changes only the absolute constant.
Variants and changes of scope
Randomized algorithm. State success probability, for example at least $2/3$ on every input, and whether runtime is worst-case or expected. Approximate envy. $v_i(A_i)+p_i\geq v_i(A_j)+p_j-\varepsilon$ is a different output requirement. Demand oracle. An oracle maximizing $v_i(S)-\sum_{g\in S}q_g$ supplies stronger access than a value oracle. Representation. An explicit table of $2^m$ bundle values and a succinct circuit have different input sizes. These choices cannot be interchanged in a complexity claim.
Audit conclusion and source relationship
Verification incomplete. The paper's title, authors, arXiv identifier, and broad subsidy topic were corroborated, but its full text was unavailable in this audit. The earlier precise Section 6 attribution has been removed. This entry is a rigorously specified candidate target; its exact attribution and current open status are not certified. It must not be counted as a verified published open problem.
References and exact source roles
[S1] Max Dupré la Tour and Mashbat Suzuki (2026). Subquadratic Subsidies for Nonnegative or Nonpositive Valuations. arXiv:2609.08272v1, 8 September 2026.
Verified locator / source role: Bibliographic identity and broad abstract topic corroborated by the indexed arXiv record. Full text could not be retrieved. The draft's claimed Section 6 locators are NOT verified and have been withdrawn.
https://arxiv.org/abs/2609.08272
Common conventions: Additional-source status and mathematical conventions
Of the 100 supplied ECON entries, 65 distinct problems appear here; 32 close matches refine earlier entries, and three duplicate questions map to existing entries. Appendix app:audited-crosswalk lists every destination. The attachment's P/R/S/U distinctions and source audits are retained. Its precise mathematical formalizations are editorial unless the individual audit says otherwise. Candidate subsidy targets ECON-004--006 retain their U flags; the resolved approval-core question ECON-007 updates OP-0202 above. The following supplied conventions govern both this part and the attributed ECON refinements elsewhere in the catalogue, subject to local restrictions.
Parameterized questions. A problem family lists inputs that must be fixed before an instance is evaluated: population, horizon, policies, information, data law, model class and welfare weights. These are required choices, not quantities the citations are assumed to specify. Undefined applications should not be treated as identified estimands.
Indices and integrability. Sets of agents, firms and regions are finite unless a population measure is explicitly used. $i,j$ index units, $r$ regions, $t$ dates and $h$ horizons. $\mathbb E$ and $\Pr$ refer to the declared population and law; $\mathbf1\{A\}$ is an indicator. Every displayed expectation and discounted sum needs existence in the stated domain. Infinite horizons use a discount in $(0,1)$ and a convergence condition; finite horizons may use discount one.
Optimization and existence. A displayed $\max$, $\min$, or $\arg\max$ is conditional on attainment. For finite feasible menus this is immediate; general spaces need continuity and compactness/coercivity or another existence argument. Without attainment, the target is the supremum/infimum and arbitrarily near-optimal feasible choices. $\inf\varnothing=+\infty$. Empty feasibility and an unidentified target are different issues.
Potential outcomes. $Y_i(z)$ is the outcome under a specified intervention, not the observed conditional mean among people choosing $z$. In binary comparisons $\Delta Y_i=Y_i(1)-Y_i(0)$. Specify assignment, treatment versions, compliance, information and observation horizon. Interference is allowed under a full policy vector; compressed exposure notation needs a justified mapping. No interference, consistency and overlap are substantive assumptions, not automatic consequences of notation.
Populations and observation. Fix baseline eligibility and population weights. Conditioning on post-policy employment, survival, relocation or program uptake can change the population being compared. Death is not ordinary loss to follow-up; outcomes truncated by death need a composite convention, joint survival target, or explicitly defined survivor stratum. Fertility-changing interventions need a population functional rather than an unexplained fixed descendant cohort. Measurement and missingness models must be supplied.
Identification. A structural model $m\in\mathcal M$ implies observable law $P_m$ and target $\theta(m)$. Identification means \[ P_{m_1}=P_{m_2}\ \Longrightarrow\ \theta(m_1)=\theta(m_2) \quad\text{for all }m_1,m_2\in\mathcal M . \] Without identification, the target is \[ \Theta(P;\mathcal M)=\{\theta(m):m\in\mathcal M,\ P_m=P\}. \] Writing $\theta(P)$ before establishing identification can hide incompatible latent models. Confidence sets additionally need a sampling law, confidence level, asymptotic sequence and uniformity class. Point identification, coverage and informative precision are separate properties.
Mediation. Total effects of randomized assignment are distinct from cross-world natural indirect effects. Belief/effort-channel effects require a meaningful mediator intervention and additional measurement, exclusion or mediation assumptions. Randomization of the initial policy alone does not supply those assumptions. Report bounds or interventional alternatives when the stronger target is unsupported.
Equilibrium. A counterfactual $W(z)$, $p(z)$, or $\mu_t^z$ requires individual optimization, feasibility, government/resource budgets, market clearing and state-transition laws. State equilibrium existence and selection, or report ranges over compatible equilibria. Initial-state integration includes subsequent endogenous transitions; current-state integration must use the policy-dependent distribution. Reduced-form invariance after policy is not assumed.
Welfare accounts. Scores, utility, health, dollars and ecological quantities require explicit conversion before addition. Fees, taxes, subsidies, wages and extortion payments are transfers between parties; distributional weights can make them welfare relevant, but their face value is not automatically a resource loss. State ownership, geographic boundaries, foreign-income weights and fiscal finance. Do not add profits to household welfare already including dividends, or count land capitalization and the underlying benefit twice. A benefit-cost expression must distinguish gross benefits from net welfare and subtract every real cost exactly once.
Derivatives and risk. Log derivatives require positive arguments; local responses require admissible perturbations and specified equilibrium branches. Differentiation under expectations needs regularity/domination, and boundaries may allow only one-sided derivatives. Risk uses a specified law; ambiguity uses a declared nonempty law set on a common history space. Adaptive policies must be nonanticipative. A robust criterion is an editorial choice unless attributed explicitly.
Scope overlaps. Allocation, collective choice, contracts, household bargaining and coordinated policy overlap economics with optimization and game theory. They are retained because they appeared in the original catalogue; no claim of a strictly game-theory-free selection is made.
Statement licence: CC-BY-4.0 · Source file
Contributions 2
GPT 6 Astra Ultra attempt on Econ-72
Polynomial-time construction with subquadratic envy-free subsidies: A sharp value-oracle algorithm for cardinality valuations
The full target asks for polynomially many exact value queries and bit operations producing envy-freeness with nonnegative subsidies of total $O(n^{3/2}\sqrt{\log(4n)})$, uniformly in the number of items. The constraints are \[ v_i(A_i)+p_i\geq v_i(A_j)+p_j\quad(i,j\in[n]), \qquad p_i\geq0. \] Here a bundle's subsidy travels with the bundle. The following algorithm gives the sharp linear bound on an explicitly nonadditive subclass.
Suppose $1\leq r<n$. Query each $h_i(q)$ and $h_i(q+1)$ on any bundles of those cardinalities, using normalization when $q=0$. Put $\delta_i=h_i(q+1)-h_i(q)\in[0,1]$. Let $H$ consist of $r$ agents with largest $\delta_i$, breaking ties arbitrarily. Give each agent in $H$ exactly $q+1$ items, and each other agent exactly $q$ items. Set \[ d=\max_{i\notin H}\delta_i,\qquad p_i=\begin{cases}0&i\in H,\\d&i\notin H.\end{cases} \] Agents with bundles of equal cardinality receive equal subsidies and see those bundles identically. If $i\notin H$ and $j\in H$, then $h_i(q)+d\geq h_i(q+1)$ because $d\geq\delta_i$. If $i\in H$ and $j\notin H$, then $h_i(q+1)\geq h_i(q)+d$ because sorting guarantees $\delta_i\geq d$. These exhaust the envy constraints. The total is $(n-r)d\leq n-r\leq n-1$.
The queries, sorting, and assignment have the claimed bounds. Differences and comparisons of $L$-bit rationals, and outputting copies of the selected difference $d$, have polynomial bit complexity. No exponentially large table of the functions is required. ∎
For the second assertion query $v_i(M)$ and select $r$ maximizing this number, with maximum $H$. Give all items to $r$, set $p_r=0$, and set every other payment to $H$. The recipient is indifferent between its bundle and an empty bundle with subsidy $H$. Each other agent weakly prefers its own subsidized empty bundle to $M$, since $v_i(M)\leq H$. All empty bundle-payment pairs coincide. Telescoping the marginal bound gives $H\leq m$, proving the total bound. ∎
In particular, the full target rate is constructively achieved on arbitrary valuations whenever $m\leq\sqrt{n\log(4n)}$. This statement is a restriction on market size, not a uniform solution for unrestricted $m$.
Source relationship and remaining gap.
The full text of Dupré la Tour and Suzuki [source], Section 6, explicitly asks for efficient construction at the stated rate. Their existence proof is not a polynomial-time algorithm. The sorting argument here uses cardinality symmetry, which removes bundle-identity information; general value oracles lack that property. The polynomial-time target for unrestricted heterogeneous monotone valuations remains unresolved here.References
- [source] M. Dupré la Tour and M. Suzuki. Subquadratic Subsidies for Nonnegative or Nonpositive Valuations, version 1, 2026, Section 6. https://arxiv.org/html/2609.08272v1.
Completion Estimate
20%GPT 6 Astra Pro attempt on Econ-72
D63-70.tex
Research attempt and adversarial audit --- 9 October 2026
FORMAL RESTATEMENT
For every $n\ge1$, finite $M$ with $m=|M|$, and family of valuations $v_i:2^M\to\mathbb Q$ satisfying \[ v_i(\varnothing)=0,\qquad 0\le v_i(S\cup\{g\})-v_i(S)\le1\quad(g\notin S), \] a value oracle returns an exact rational of encoding length at most the supplied bound $L$. Does there exist an absolute $C$ and an algorithm using $\operatorname{poly}(n,m,L)$ oracle calls and bit operations that outputs a complete allocation and nonnegative rational payments with \[ v_i(A_i)+p_i\ge v_i(A_j)+p_j\quad(\forall i,j),\qquad \sum_i p_i\le C n^{3/2}\sqrt{\log(4n)}? \] Logarithms are natural. The same constant and polynomial must work for all inputs. A randomized variant must specify probability of success and the runtime convention; our restricted algorithms are deterministic. Approximate envy, demand-oracle access, explicit exponential tables and succinct circuits are different models. Empty bundles and zero valuations are allowed. A feasible output must have polynomial encoding length; exact irrational output is not authorized.QUICK LITERATURE/CONTEXT CHECK
The previously inaccessible source is now readable. Its Theorem 1 gives an existential bound $5\sqrt2(n-1)^{3/2}\sqrt{\log(4n)}$ for nonnegative bundle values under the absolute marginal bound; monotone goods satisfy those hypotheses. Section 6 asks about efficient computation [subq]. Thus existence at the requested scale is not the missing step here.ATTACK PLAN
The proof track isolates polynomial-time payment computation and searches for partitions in tractable subdomains. The construction track tests positive-cycle obstructions and small nonadditive examples. A full enumeration supplies an exact benchmark, but is not confused with a polynomial value-oracle algorithm.| Tool | Role |
| Difference constraints | Characterize exactly which partitions admit subsidies. |
| Longest-path potentials | Give minimal nonnegative payments and a certificate. |
| Finite welfare-maximizing assignment | Ensures feasibility for at least one bundle assignment. |
| Prefix crossing | Produces the sharp two-agent bound. |
| Greedy load balancing | Solves identical monotone valuations. |
| Oracle/bit-complexity accounting | Separates evaluation of a certificate from finding it. |
| Small Lipschitz set-function search | Tests nonadditive and mixed-sign boundary cases. |
| Topological/discrepancy methods | Possible route to global bounds, but not a polynomial algorithm by themselves. |
WORK
A complete payment certificate for a fixed partition
Any nonnegative feasible $p$ dominates every path weight starting at $i$: sum the edge inequalities along that path and use nonnegativity of its final payment. Hence $p_i\ge p_i^*$ for every $i$. If the minimum coordinate of $p^*$ were positive, subtracting it from all coordinates would give a strictly smaller nonnegative feasible vector, a contradiction.
To obtain some envy-freeable allocation, begin with any $n$ bundle occurrences, including empty occurrences, forming a partition. Choose an assignment of those bundles to the agents that maximizes total value over the finite set of $n!$ assignments. A positive cycle in its envy graph would reassign the bundles cyclically and strictly increase that total, an impossibility. Finally there are finitely many complete allocations. Each feasible one has the attained minimum total $\sum_i p_i^*$, and at least one is feasible; taking the smallest of finitely many such totals proves attainment of $s(v)$. ∎
A sharp theorem for two agents, even without monotonicity
Fix this bipartition $S,T$. Write $d_i=v_i(S)-v_i(T)$. If $d_1\ge d_2$, assign $S$ to agent 1 and $T$ to agent 2. The constraints on the payment difference are \[ d_2\le p_2-p_1\le d_1. \] Choose the element of this closed interval nearest zero; its absolute value is the minimum possible total nonnegative subsidy, by placing that amount on the appropriate agent and zero on the other. If $d_1<d_2$, reverse the bundles and apply the same argument to $-d_1,-d_2$. The resulting minimum total is zero if $d_1,d_2$ straddle zero, and otherwise $\min\{|d_1|,|d_2|\}$. It is therefore at most one. Scanning the prefixes requires $O(m)$ queries and the final pair of values for agent 2; all arithmetic is exact for rational inputs.
For sharpness, use one good valued at one by both agents. Whichever receives it, the other needs a subsidy exactly one larger than the recipient's. Nonnegative payments therefore have total at least one, achieved by paying the nonrecipient one and the recipient zero. ∎
Identical monotone valuations: a linear constructive bound
A complete but exponential algorithm
VERIFICATION
The executable checks generated normalized integer set functions of the form \[ v(S)=\min_r\{c_r+|S\triangle K_r|\}-\min_r\{c_r+|K_r|\}. \] Each cone is 1-Lipschitz for the Hamming metric, and the pointwise minimum is also 1-Lipschitz: using a minimizing index at one endpoint gives one direction of the inequality, and interchanging endpoints gives the other. The program additionally checked every one-item marginal explicitly. With seed 20261009, it tested 200 two-agent/five-item instances and 200 three-agent/four-item instances. It enumerated every complete allocation, computed exact minimum payments by the recurrence, and found largest observed optima of one in both batches. These are nonuniform small samples, not worst-case asymptotic bounds; many generated valuations are not monotone.
\begin{lstlisting} for each sampled valuation table v: best = infinity for each complete allocation A: w[i,j] = v[i,A[j]] - v[i,A[i]] p = longest-walk recurrence from zero if p passes all envy constraints: best = min(best,sum(p)) retain exact best and a witnessing allocation \end{lstlisting} The one-good lower example was verified algebraically for every $n$, not inferred from this sample. Boundary checks include $n=1$, no items, zero values, zero-weight cycles, and exact rational payment differences. No positive-cycle partition is declared feasible merely because one or more agents could be paid a large amount: a positive cycle makes every payment vector impossible.The arbitrary-table tests stress the payment evaluator on a larger domain; they are not themselves evidence that the original monotone oracle problem is hard. The identical-valuation algorithm uses only the promised common oracle values. The longest-path computation proves that once an appropriate partition is known, irrational payments and unbounded output length are not barriers. It does not bound the search for that partition. A demand-oracle subroutine is nowhere substituted for a value query.
FINAL
LABEL: UNRESOLVED. The target polynomial value-oracle algorithm is neither proved nor ruled out. Exact polynomial certificate evaluation, the sharp two-agent case, an all-$n$ identical-valuation algorithm and a correct exponential benchmark are fully established.Exact first gap. No polynomial-query method is provided for finding, among all complete partitions, one whose minimum payment vector has total $O(n^{3/2}\sqrt{\log n})$ under heterogeneous monotone valuations.
Three next moves. (1) Find a polynomially evaluable separation or descent oracle for a partition potential tied to minimum subsidies. (2) Turn a fractional or topological existence certificate into an explicit finite rational search region with polynomial complexity. (3) Build a value-oracle indistinguishability family whose low-subsidy partitions reveal a hidden bundle, and prove a genuine query lower bound rather than treating nonconstructivity as hardness.
Minimal hard instance. At least three nonidentical valuations are needed to escape the two elementary algorithms here; sharply context-dependent marginal values are a plausible obstruction. No lower-bound family is certified by the small random search.
Completion Estimate
20%Exact payment computation and important restricted cases are complete; the main heterogeneous value-oracle search problem remains unresolved. The existing existential result is credited separately.
This is a subjective estimate of the fraction of the whole requested mathematical scope addressed by this report, including the named variants. It is not a probability of correctness, an objectively measured fraction of a proof, or an estimate that the remaining work takes the complementary fraction of the time. Only the eleven supplied files are assessed; no missing rank-1--200 statements are inferred.
References
- [subq] M. Dupré la Tour and M. Suzuki. Subquadratic Subsidies for Nonnegative or Nonpositive Valuations. arXiv:2609.08272v1, 8 September 2026, Theorem 1 and Section 6. https://arxiv.org/html/2609.08272v1.