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on Economic Design |
| By: | Mira Frick; Ryota Iijima; Yuhta Ishii; Nicholas Wu |
| Abstract: | Consider an auction with buyers whose values depend on an underlying state (e.g., market fundamentals). How does the auction format shape the information that buyers' bids reveal about the state? We recast auctions as statistical experiments and compare different auction formats in terms of the (Lehmann) informativeness of the induced experiments. Our main finding is that among a large class of auctions (e.g., $k$th-price, all-pay), the first-price auction is the most informative. As a result, this auction guarantees the highest payoffs to a decision-maker who uses the information revealed by buyers' bids in a monotone decision problem (e.g., a prediction problem or the choice of a reserve price in a future auction). |
| Date: | 2026–09 |
| URL: | https://d.repec.org/n?u=RePEc:arx:papers:2609.21168 |
| By: | Zhiqiang Zhuang; Quan Yu; Yisong Wang; Kewen Wang; Zhe Wang |
| Abstract: | The return-on-investment (ROI) constraint is central to many auctions, particularly in online advertising, where a bidder is unwilling to pay more than a fixed fraction of the value obtained. We study truthful and revenue-maximizing auctions for ROI-constrained bidders. We first characterize truthful auctions when both valuations and ROI constraints are private, showing that the allocation rule uniquely determines the payment rule. Building on this characterization, for multiple bidders we introduce $\sigma$-increment mechanisms that resemble Myerson's optimal mechanism~\cite{journals/mor/Myerson81}; as $\sigma$ vanishes, these mechanisms become asymptotically optimal among deterministic truthful mechanisms, and their revenue approaches at least a $1/\bar r$ fraction of the optimal expected revenue over all truthful mechanisms, where $\bar r$ is the largest possible ROI constraint. In the single-bidder setting, we prove that every truthful auction can be replaced by a convex pricing function with weakly higher payments for every type, and we derive the optimal pricing functions when either the valuation or the ROI constraint is public. |
| Date: | 2026–09 |
| URL: | https://d.repec.org/n?u=RePEc:arx:papers:2609.16522 |
| By: | Frank Stähler; Andrea Tulli |
| Abstract: | We study bidding in a broad class of price-based procurement mechanisms in which the lowest bid does not always win. These mechanisms are used when cost overruns and non-compliance affect contract execution. We first characterize equilibrium bidding behavior in a general setting with endogenous winning probabilities. We then analyze mixed auction formats in which bidders face uncertainty about the allocation rule, as in the Italian system where a lowest-price or average bid rule is selected based on participation. We show that increasing reliance on the latter can improve compliance but raises bids and expected payments, highlighting a trade-off between contract performance and low award prices. |
| Keywords: | procurement, average bid auction, cost overrun |
| JEL: | H57 D44 |
| Date: | 2026 |
| URL: | https://d.repec.org/n?u=RePEc:ces:ceswps:_12970 |
| By: | Szilvia Pápai (Concordia University) |
| Abstract: | Matching mechanisms differ in how much of an agent's preference ranking must be determined and reported to obtain a particular object. A mechanism is singleton-attainable (SA) if every object that an agent can obtain through some report can also be obtained by reporting only that object as acceptable. With an SA mechanism, once an attainable object has been identified, the agent need not rank or report any other object. Singleton-attainability identifies a distinct dimension in matching theory and market design: transparent access to attainable outcomes, separate from incentives, stability, welfare or equity. We establish general conditions for SA and derive its strategic implications. Top-lift invariance and truncation invariance together imply SA, while strategyproofness and stability each imply SA. By contrast, no Pareto improvement over a strategyproof, individually rational, and non-wasteful mechanism is SA. In particular, every Pareto improvement over Deferred Acceptance violates SA. We introduce report width, which measures how many acceptable objects may have to be reported to obtain an object. SA mechanisms have report width one. Report width is unbounded for a large class of efficient mechanisms that Pareto-improve Deferred Acceptance. Stable selection with report-induced priorities has width one when priorities are monotone and maximal width under reverse priority dominance. Rank-welfare maximization has width one when the outside-option rank is fixed and maximal width when it is report-dependent. These results reveal a structural divide, which we call the width dichotomy: across all mechanisms and families in our classification and all structural classes we study, report width is either one or unbounded. Matching mechanisms differ in how much of an agent's preference ranking must be determined and reported to obtain a particular object. A mechanism is singleton-attainable (SA) if every object that an agent can obtain through some report can also be obtained by reporting only that object as acceptable. With an SA mechanism, once an attainable object has been identified, the agent need not rank or report any other object. Singleton-attainability identifies a distinct dimension in matching theory and market design: transparent access to attainable outcomes, separate from incentives, stability, welfare or equity. We establish general conditions for SA and derive its strategic implications. Top-lift invariance and truncation invariance together imply SA, while strategyproofness and stability each imply SA. By contrast, no Pareto improvement over a strategyproof, individually rational, and non-wasteful mechanism is SA. In particular, every Pareto improvement over Deferred Acceptance violates SA. We introduce report width, which measures how many acceptable objects may have to be reported to obtain an object. SA mechanisms have report width one. Report width is unbounded for a large class of efficient mechanisms that Pareto-improve Deferred Acceptance. Stable selection with report-induced priorities has width one when priorities are monotone and maximal width under reverse priority dominance. Rank-welfare maximization has width one when the outside-option rank is fixed and maximal width when it is report-dependent. These results reveal a structural divide, which we call the width dichotomy: across all mechanisms and families in our classification and all structural classes we study, report width is either one or unbounded. Matching mechanisms differ in how much of an agent's preference ranking must be determined and reported to obtain a particular object. A mechanism is singleton-attainable (SA) if every object that an agent can obtain through some report can also be obtained by reporting only that object as acceptable. With an SA mechanism, once an attainable object has been identified, the agent need not rank or report any other object. Singleton-attainability identifies a distinct dimension in matching theory and market design: transparent access to attainable outcomes, separate from incentives, stability, welfare or equity. We establish general conditions for SA and derive its strategic implications. Top-lift invariance and truncation invariance together imply SA, while strategyproofness and stability each imply SA. By contrast, no Pareto improvement over a strategyproof, individually rational, and non-wasteful mechanism is SA. In particular, every Pareto improvement over Deferred Acceptance violates SA. We introduce report width, which measures how many acceptable objects may have to be reported to obtain an object. SA mechanisms have report width one. Report width is unbounded for a large class of efficient mechanisms that Pareto-improve Deferred Acceptance. Stable selection with report-induced priorities has width one when priorities are monotone and maximal width under reverse priority dominance. Rank-welfare maximization has width one when the outside-option rank is fixed and maximal width when it is report-dependent. These results reveal a structural divide, which we call the width dichotomy: across all mechanisms and families in our classification and all structural classes we study, report width is either one or unbounded. Matching mechanisms differ in how much of an agent's preference ranking must be determined and reported to obtain a particular object. A mechanism is singleton-attainable (SA) if every object that an agent can obtain through some report can also be obtained by reporting only that object as acceptable. With an SA mechanism, once an attainable object has been identified, the agent need not rank or report any other object. Singleton-attainability identifies a distinct dimension in matching theory and market design: transparent access to attainable outcomes, separate from incentives, stability, welfare or equity. We establish general conditions for SA and derive its strategic implications. Top-lift invariance and truncation invariance together imply SA, while strategyproofness and stability each imply SA. By contrast, no Pareto improvement over a strategyproof, individually rational, and non-wasteful mechanism is SA. In particular, every Pareto improvement over Deferred Acceptance violates SA. We introduce report width, which measures how many acceptable objects may have to be reported to obtain an object. SA mechanisms have report width one. Report width is unbounded for a large class of efficient mechanisms that Pareto-improve Deferred Acceptance. Stable selection with report-induced priorities has width one when priorities are monotone and maximal width under reverse priority dominance. Rank-welfare maximization has width one when the outside-option rank is fixed and maximal width when it is report-dependent. These results reveal a structural divide, which we call the width dichotomy: across all mechanisms and families in our classification and all structural classes we study, report width is either one or unbounded. Matching mechanisms differ in how much of an agent's preference ranking must be determined and reported to obtain a particular object. A mechanism is singleton-attainable (SA) if every object that an agent can obtain through some report can also be obtained by reporting only that object as acceptable. With an SA mechanism, once an attainable object has been identified, the agent need not rank or report any other object. Singleton-attainability identifies a distinct dimension in matching theory and market design: transparent access to attainable outcomes, separate from incentives, stability, welfare or equity. We establish general conditions for SA and derive its strategic implications. Top-lift invariance and truncation invariance together imply SA, while strategyproofness and stability each imply SA. By contrast, no Pareto improvement over a strategyproof, individually rational, and non-wasteful mechanism is SA. In particular, every Pareto improvement over Deferred Acceptance violates SA. We introduce report width, which measures how many acceptable objects may have to be reported to obtain an object. SA mechanisms have report width one. Report width is unbounded for a large class of efficient mechanisms that Pareto-improve Deferred Acceptance. Stable selection with report-induced priorities has width one when priorities are monotone and maximal width under reverse priority dominance. Rank-welfare maximization has width one when the outside-option rank is fixed and maximal width when it is report-dependent. These results reveal a structural divide, which we call the width dichotomy: across all mechanisms and families in our classification and all structural classes we study, report width is either one or unbounded. |
| Keywords: | matching theory, market design, singleton-attainability, report width, preference reporting, school choice, deferred acceptance, strategyproofness |
| JEL: | C78 D47 |
| Date: | 2026–09–22 |
| URL: | https://d.repec.org/n?u=RePEc:crd:wpaper:26001 |
| By: | Takeshi Nishimura; Nobuyuki Hanaki |
| Abstract: | We provide experimental evidence on entry and bidding behavior in surplusextracting auctions built on the second-price format. In addition to the simple second-price auction, we consider full- and partial-surplus-extracting auctions. The latter leaves more surplus to bidders under full entry than the former, while preserving the same set of undominated strategies: value bidding and opting out. In contrast to the second-price auction, both auctions exhibit lower entry and overbidding among entrants. Our findings highlight the interplay between entry and bidding behavior, shedding light on the trade-off between surplus extraction and strategic simplicity in auction design with voluntary participation. |
| Date: | 2024–11 |
| URL: | https://d.repec.org/n?u=RePEc:dpr:wpaper:1266r |
| By: | Linnenbrink, Daniel |
| Abstract: | European policymakers argue that bidding zones with uniform prices ensure fairness in electricity markets. Since the outcome of such a fair spot market is often infeasible due to network constraints, a second stage is needed: the redispatch. I establish a mechanism design result showing that even a minimal fairness restriction on the first stage strictly increases procurement costs for asymmetric dispatches. In detail, I analyze a market-based redispatch mechanism where inc-dec gaming creates arbitrage profits for those producers that benefit the network the least. These results identify a general cost of fairness in sequential markets and question uniform bidding zones in electricity markets. |
| Keywords: | mechanism design, fairness, electricity market design |
| JEL: | D47 D82 L94 Q48 |
| Date: | 2026 |
| URL: | https://d.repec.org/n?u=RePEc:zbw:zewdip:343566 |
| By: | Carmelo Rodríguez à lvarez (ICAE Instituto Complutense de Análisis Económico, Depto. Análisis Económico y Economía Cuantitativa, Universidad Complutense de Madrid) |
| Abstract: | We investigate interval selection problems in which a society chooses an interval from a discrete ordered set. We consider a domain of interval-monotonic preferences, where each voter has an interval of acceptable integers, benefits from enlarging the selected interval by including acceptable integers, and is worse off when unacceptable integers are included. We study how different institutional frameworks affect the design of strategy-proof interval choice functions. In particular, we distinguish between unrestricted interval selection and the expansion of a commonly accepted status quo interval. We show that the latter transforms interval selection into a separable multidimensional choice problem, whereas unrestricted interval selection remains intrinsically multidimensional. This institutional distinction leads to fundamentally different characterizations of strategy-proof interval choice functions. |
| Keywords: | Strategy-proofness, Interval Choice Function, Interval-monotonic Preference. |
| JEL: | C72 D71 |
| Date: | 2026 |
| URL: | https://d.repec.org/n?u=RePEc:ucm:doicae:2601 |
| By: | David Martimort (TSE-R - Toulouse School of Economics - UT Capitole - Université Toulouse Capitole - Comue de Toulouse - Communauté d'universités et établissements de Toulouse - EHESS - École des hautes études en sciences sociales - CNRS - Centre National de la Recherche Scientifique - INRAE - Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement, IUF - Institut universitaire de France - M.E.N.E.S.R. - Ministère de l'Education nationale, de l’Enseignement supérieur et de la Recherche); Aggey Semenov (uOttawa - Université d'Ottawa = University of Ottawa [Ontario]) |
| Abstract: | We characterize the optimal contract within the class of fixed-terms mechanisms in a repeated buyer-seller relationship with persistent adverse selection and one-sided limited enforcement. The seller reports his type once, and the corresponding transfer and output are then repeated in every period. After receiving the current transfer, the seller may breach, pay an enforceable penalty, and terminate the relationship. In this benchmark, the enforcement problem collapses to a bound on the transfer targeted to the most efficient type. This yields a three-regime characterization. With strong enforcement, the repeated static second-best contract is feasible. With weak (intermediate) enforcement, the top transfer is capped, inducing bunching among efficient types and additional downward distortions. With very weak enforcement, sustaining compliance through public penalties alone would require excessive quantity distortions, and the optimal contract instead leaves strictly positive continuation rents, including for the least efficient type. We interpret the associated distortion as a virtual enforcement cost. |
| Keywords: | Adverse selection, Limited enforcement, Relational contracts, Contract breach |
| Date: | 2026–10 |
| URL: | https://d.repec.org/n?u=RePEc:hal:journl:hal-05742834 |
| By: | Semin Kim (Yonsei University) |
| Abstract: | Under independent generic beliefs, unanimity and ordinal Bayesian incentive compatibility (OBIC) imply dictatorship. We study where this conclusion first fails as genericity is relaxed, in the minimal nontrivial environment of two voters, three alternatives, and the unrestricted domain of strict preferences. We obtain an exact classification of the exceptional balance relations and the mechanisms they support, without imposing any further symmetry on the ranking distribution. Among the 301 reduced genericity relations, only pairwise-balance relations-those equating the probabilities that two alternatives defeat a common benchmark-can support a non-dictatorial unanimous deterministic OBIC rule when exactly one marginal satisfies a single genericity relation and the other remains generic. In this one-sided case, exactly five rules are OBIC, including three non-dictatorial unilateral agenda mechanisms. Under i.i.d. beliefs, the only additional relation type is top balance-equality of first-choice probabilities for two alternatives-which supports a unique non-dictatorial agreement-or-default rule. These two exceptional relation types operate through distinct approval and agreement channels, respectively, and both channels persist in larger lectorates. |
| Keywords: | ordinal Bayesian incentive compatibility; genericity; social choice; voting rules; dictatorship. |
| JEL: | D71 D72 D82 |
| Date: | 2026–09 |
| URL: | https://d.repec.org/n?u=RePEc:yon:wpaper:2026rwp-296 |
| By: | Victor H. Aguiar; Dian Hong |
| Abstract: | In large markets, scarce attention limits partner evaluation and creates allocation loss, which stability magnifies. In an independent random market with average executable degree $d$, unmatched shares fall at rates $e^{-\sqrt d}$ under stability and $e^{-d}$ under maximum matching on the same graph. Changing consideration can make applications rejected in a provisional active-screen computation relevant again. Exact query-neutral implementation must retain allocation-relevant off-screen authorizations; otherwise, missing authorization must be reacquired. Limited-attention deferred acceptance (LA-DA) preserves valid authorizations and reengages eligible pairs. Conditional on exact next-best information and persistent execution rights, adaptive discovery saves a logarithmic factor in reached proposals relative to independent exposure. In an application to speed dating, bilateral reports let us compare stable and maximum matching on restricted graphs, separating missed opportunities from same-graph stability loss. In Chilean school choice, we document 9, 502 applicants accepting higher-ranked or new placements through retained rankings. |
| Date: | 2026–09 |
| URL: | https://d.repec.org/n?u=RePEc:arx:papers:2609.09693 |
| By: | Shota Ichihashi; Fei Li; Dihan Zou |
| Abstract: | We study peer monitoring design in knowledge production. A principal leads agents who work on different but related tasks. By working on their own tasks, agents acquire information that is useful for evaluating their peers' performance. We consider robust contracts under which effort by all agents is the unique rationalizable outcome. The optimal contract induces a hierarchy of monitoring authority: agents easier for the principal to monitor directly are assigned greater authority to evaluate other agents. Task diversity improves information value but weakens peer monitoring. This tension distorts optimal public task assignment toward the principal's core expertise. Confidential random assignment relaxes this distortion by decoupling information production from the perceived monitoring structure. |
| Date: | 2026–09 |
| URL: | https://d.repec.org/n?u=RePEc:arx:papers:2609.10499 |
| By: | Jason Milionis; William Pires |
| Abstract: | This paper is the first work at the intersection of game theory and property testing, giving algorithms and lower bounds for efficiently testing whether an allocation mechanism is incentive compatible (IC). We propose distinguishing whether a mechanism is $\epsilon$-far from being IC, i.e., when it observes many monotonicity "violations." Conceptually, inspired by the literature on Boolean function monotonicity testing, we construct a tester for discrete single-parameter allocation rules. Technically, our work is the first to consider monotonicity testing of vector-valued functions on the hypergrid. We give a $\tilde{O}(n/\epsilon)$-query algorithm to test whether a function (representing n-player allocation mechanisms) is coordinate-wise monotone versus $\epsilon$-far from it. We also show a matching lower bound: the class of coordinate-wise monotone vector-valued functions on a Boolean hypercube or hypergrid requires $\tilde{\Omega}(n/\epsilon)$ queries to test whether it is $\epsilon$-far from monotonicity, and this holds even if the tester is two-sided and allowed to make adaptive queries. Finally, we extend our upper bound to and give a tester of the same query complexity for pricing functions of allocation mechanisms. This requires overcoming the technical challenge that the path in function space to the closest IC mechanism may involve interdependent changes to both the price and the allocation rule. |
| Date: | 2026–09 |
| URL: | https://d.repec.org/n?u=RePEc:arx:papers:2609.17406 |
| By: | Xinyue Fu (Institute of Chinese Financial Studies, Southwestern University of Finance and Economics, Sichuan, China); Zhenjiang Qin (University of Macau, Faculty of Business Administration, Macau) |
| Abstract: | We develop an analytical model featuring two public signals on a terminal payoff: an early public signal (e.g., a social-media signal or an alternative-data signal) and a later official disclosure. Both signals arrive before a final payoff in an incomplete market characterized by investors with heterogeneous prior precisions. We demonstrate that error correlation across these public signals is a first-order driver of speculative surplus, price variance, and trading volume. This correlation determines the incremental informational value of the official disclosure relative to the early public signal, and the incremental precision is U-shaped in the error correlation. Moreover, a precision paradox might exist in the modern Big Data era in which early public signals (e.g., an aggregate alternative-data signal) can be more precise than official disclosure: increasing the official signal's precision under high error correlation can paradoxically reduce its marginal value. We investigate information design by studying how a regulator trades off investors' welfare (speculative surplus) against market stability (price variance). We discuss how to implement an optimal information design and show that changing the error correlation via, e.g., changes in disclosure timing, verification protocols, or measurement methodology, can be cheaper and more effective than simply increasing the official signal precision. |
| Keywords: | public signal, social media, alternative data, official disclosure, correlation, cost of capital, trading volume, information design |
| Date: | 2026–09 |
| URL: | https://d.repec.org/n?u=RePEc:boa:wpaper:202647 |
| By: | Natalie Collina; Surbhi Goel; Aaron Roth; Sikata Bela Sengupta |
| Abstract: | Long-running AI agents create a control problem: each action they take changes the state, which in turn affects the trajectory of future actions. If the agent is not fully aligned, then guaranteeing safety requires approving consequential actions before allowing them to be executed. But requiring human approval at every step makes attention a bottleneck. Delegating review to other AI agents raises the same alignment problem: the reviewers may themselves be misaligned. We identify a condition on a reviewing panel that is weaker than individual alignment yet necessary and sufficient for a guarantee that the principal fares at least as well in expectation as under a designated baseline policy. Each reviewer agent reports whether an action proposal made by a proposer agent improves its own utility relative to the baseline. We show that a threshold rule tolerating $k$ disapprovals is safe exactly when, after any $k$ reviewers are removed, the principal's utility can be written as a nonnegative combination of the remaining reviewers' utilities, plus a term that is nonnegative on every feasible proposal. We call this property $k$-robust coalitional alignment. The characterization lifts to sequential control: in a discounted MDP with an arbitrary proposer agent, safety at every state is both necessary and sufficient for the induced policy to match or improve on the baseline. When reviewers vote strategically, full-panel coverage in reward-function space guarantees that every Nash equilibrium is safe under the unanimous approval rule; in contrast, more permissive thresholds can admit unsafe equilibria even when reviewers are individually aligned. Experiments with existing reviewer models show that collective review can remain sound without an aligned individual, even when some disapprovals are tolerated. |
| Date: | 2026–09 |
| URL: | https://d.repec.org/n?u=RePEc:arx:papers:2609.15803 |
| By: | Bo Cowgill |
| Abstract: | Forecasts guide decisions, but an expert who privately values the decision may misreport beliefs to influence it. We study contracts that jointly elicit the expert's belief about a verifiable state and her stake in a binary action. When agents with different stakes can hold the same belief, exact belief-only IC forces the action to ignore the report. Joint screening permits responsiveness but may require implementation rent. For thresholds, minimum implementation rent equals the distribution-weighted positive curvature of the belief-dependent cutoff. Optimal threshold design is rent-adjusted concavification. We give sufficient conditions for unrestricted threshold optimality and, beyond them, bounds and a direct optimality certificate. |
| Date: | 2026–09 |
| URL: | https://d.repec.org/n?u=RePEc:arx:papers:2609.23285 |
| By: | Charles Po-Cheng Huang; Gunhaeng Lee |
| Abstract: | Many allocation rules give priority to applicants satisfying favored conditions, including disability, homelessness, and veteran status. Because these conditions are not directly observed, a rule ranking applicants by characteristics must first determine what submitted certificates prove. This paper studies allocation with hard but partial evidence: a disability document may prove disability without proving the absence of a disqualifying tenancy record. A claim is certifiable exactly when every intended claimant has a feasible certificate excluding all outsiders. Chain rules---scores, lexicographic orders, and scalar rankings---require certification of every priority cutoff, whereas reserve rules require certification of each eligibility class. Allocation rules thus select the claim family to be certified. When certification fails, canonical repairs demote unsupported chain priorities and delete unsupported reserve labels. Nonempty reserve eligibility classes can be represented as upper contours of a single chain if and only if they are nested. A housing application illustrates the consequences. |
| Date: | 2026–09 |
| URL: | https://d.repec.org/n?u=RePEc:arx:papers:2609.21335 |
| By: | Alex Chan |
| Abstract: | Spectrum repacking auctions can restore feasibility along two margins: retiring a station via buyout or relaxing a pairwise engineering restriction. I represent stations as vertices in a network and interference restrictions as edges between them, and so station buyouts delete vertices and engineering waivers relax edges. This paper shows that buying out any one station can reduce the number of channels needed, even though relaxing any single interference restriction cannot. The smallest feasible number of channels is k . For every k≥4, I show that there is a network in which removing any station saves one channel, while relaxing any single pairwise restriction does not. This main result follows directly from Dirac’s half-century-old conjecture on vertex-critical graphs, whose chromatic number falls after any vertex is removed. By constructing the missing counterexample at k=4 and combining it with earlier results for k≥5, I show that at every k≥4, some k-vertex-critical graph has no critical edge, resolving Dirac's conjecture. Market designers auditing feasibility link-by-link systematically can mistake combinatorial complementarity for remedy failure, overlooking station buyouts that unlock the clearing target. |
| JEL: | C6 C61 D44 D47 L96 |
| Date: | 2026–09 |
| URL: | https://d.repec.org/n?u=RePEc:nbr:nberwo:35757 |
| By: | Achille Basile; K. P. S. Bhaskara Rao; Surekha Rao |
| Abstract: | We study anonymous binary social choice functions on the universal weak-preference domain when the society of voters is countably infinite. Voters may strictly support one of the two alternatives or be indifferent, and non-manipulability is required in the form of coalitional strategy-proofness. Full anonymity reduces the relevant information about a coalition not to its cardinality alone, but to its cardinality signature: finite of size \(k\), infinite with infinite complement, or cofinite with complement of size \(k\). Recording the signatures of the two strict-support coalitions yields an infinite triangular grid, ordered by increasing support for one alternative and decreasing support for the other. We prove that anonymous coalition strategy-proof binary social choice functions are exactly those obtained from super order closed subsets, i.e. upper sets, of this grid. We then give a geometric classification of these subsets. Unlike in the finite-voter case, they need not be generated by their minimal elements: countable infinity creates missing-boundary regions corresponding to finite opposition or cofinite strict support. We prove an exact representation of these subsets by genuine or missing-boundary corners, and derive a nonredundant parametrization by an antichain and, when necessary, one exceptional missing-boundary region. This yields four generalized zigzag forms and completes the infinite-society counterpart of the known geometric representation for finite electorates. |
| Date: | 2026–09 |
| URL: | https://d.repec.org/n?u=RePEc:arx:papers:2609.17836 |
| By: | Genta Okada |
| Abstract: | Moving from geographically fragmented to pooled waiting lists in deceased-donor organ transplantation can improve efficiency, but it raises concerns about regional fairness and participation incentives. This paper studies Pareto gains from such transitions in a multi-class queueing model with impatient agents, perishable items, and a tractable homogeneous compatibility friction. Unlike standard approaches that focus on static match quality or ignore regional incentives in dynamic settings, our analysis identifies dynamic risk pooling as the main source of Pareto improvements for regions: pooling reduces organ waste due to stochastic supply-demand fluctuations, temporal mismatches, and random compatibility outcomes. Although this dynamic surplus theoretically permits Pareto improvements, a purely utilitarian policy that treats all patients equally across regions often fails to deliver them when regions are asymmetric. In such cases, utilitarian redistribution extracts too many organs from high-supply regions and violates their participation constraints. To resolve this conflict, we show that the set of achievable utilities can be described by mixtures of static priority index policies. Building on this structure, we propose the Constrained Pareto Frontier Search (CPFS), a polynomial-time procedure that computes an approximately optimal allocation policy with arbitrarily small participation-constraint violations. The results suggest that, by adjusting priority indices to keep redistribution within the gains from pooled supply, demand, and compatibility risk, policymakers can attain global efficiency while preserving local participation incentives. |
| Date: | 2026–09 |
| URL: | https://d.repec.org/n?u=RePEc:arx:papers:2609.18147 |
| By: | Abrell, Jan; Rausch, Sebastian |
| Abstract: | By extending carbon pricing to buildings and road transport through ETS2, the European Union is undertaking a major policy experiment in market creation. ETS2 overlaps national emissions budgets and technology requirements, raising a general question: when does a legal market govern allocation? We distinguish three functions of market effectiveness: scarcity, exchange, and allocation authority. Completing exchange and allocation authority lowers present-value EU policy costs over 2028-2048 by 25.5%, or EUR 1.33 trillion relative to legal market creation only. Allocation authority accounts for 76% of savings; 88% of member states benefit. Compensating remaining losses requires EUR 6 billion, only 0.2% of ETS2 revenues. Restoring allocation authority raises the allowance price but lowers policy cost, implying that the endogenous carbon price in an ETS is not a sufficient statistic for welfare across institutional designs. |
| Keywords: | Carbon pricing, Emissions trading, Market design, EU ETS2, Effort Sharing Regulation, Equilibrium modelling |
| JEL: | H23 Q54 Q58 C68 |
| Date: | 2026 |
| URL: | https://d.repec.org/n?u=RePEc:zbw:zewdip:343564 |
| By: | Meryem Essaidi |
| Abstract: | Complementary resources are often allocated by agencies that see different coordinates of an individual's needs. If an intervention requires complementary resources, an agency may know if said person lacks its own resource; yet not know if supplying completes a useful bundle. We study allocation of $m$ divisible complementary goods when each agency observes only its own coordinate of a baseline-access profile. To isolate information from incentives, we measure the welfare cost of this split against a generous decentralized benchmark DEC: the best rule that acts on local information alone, with cooperative agencies and known population distribution and capacities. Even so, local observation alone can make optimally coordinated policies arbitrarily inefficient: a factor linear in $m$ (even with equal capacities), and a factor inverse in OPT (with but three agencies). Threshold referrals recover much of this loss: an agency reports if its value lies below a public threshold, and a clearing rule uses only the joint reports. Aggregating types by their reports captures a rectangle under the optimal half-utility survival curve. Our main tool is a profile-level charging certificate: if optimal utility is at least twice a threshold, OPT pays at least that on every deficient coordinate. This yields welfare at least ${\rm OPT}/[4(1+\ln(2/{\rm OPT}))]$ with one bit per agency; and an equal-revenue family shows this log-loss tight for one threshold. A geometric threshold ladder improves this to a constant fraction of OPT with doubly-logarithmic messages: a staircase recovers ${\rm OPT}/8$ with $\Theta(\log\log(1/{\rm OPT}))$ bits, and this is necessary within the class. The results isolate how a simple reporting language turns large local-info losses into constant-factor recovery. In short: One threshold gets a log-approximation. A staircase, with log-of-log bits, a constant-factor. |
| Date: | 2026–09 |
| URL: | https://d.repec.org/n?u=RePEc:arx:papers:2609.14301 |
| By: | Le Breton, Michel; Konishi, H.; Weber, Shlomo |
| Abstract: | In this paper, we define additive dyadic social interactions games (ADG), in which each player cares not only about the selected action, but also about interactions with other players, especially those who choose the same action. This class of games includes alliance formation games, network games, and discrete choice problems with network externalities. While it is known that games in the ADG class admit a pure strategy Nash equilibrium that is a maximizer of the game ís potential, the potential approach does not always apply if all coalitional deviations are allowed. In this paper, we systematically identify both restrictions on possible coalitional deviations to preserve the potential function and types of equilibria that ensures their existence for various subclasses of ADG or its subclasses, extending the approach taken by Le Breton et al. (2021). An additional avenue of our results is the examination of games with outside option which expand the set of alternatives. Although this modification complicates the analysis significantly, positive results are obtained with different class of restrictions. |
| Date: | 2026–09 |
| URL: | https://d.repec.org/n?u=RePEc:tse:wpaper:132076 |