Revealing information -- or not -- in a social network of traders
揭示信息——或不揭示——在交易者社交网络中
AI总结 基于Kyle(1985)的资产交易微观基础模型,研究知情交易者为何可能主动分享信息,并发现均衡中信息部分揭示,导致价格不完全反映资产回报,影响社会剩余分配。
揭示信息——或不揭示——在交易者社交网络中
Patrick Allmis, Paolo Pin, Fernando Vega Redondo
AI总结 基于Kyle(1985)的资产交易微观基础模型,研究知情交易者为何可能主动分享信息,并发现均衡中信息部分揭示,导致价格不完全反映资产回报,影响社会剩余分配。
我们基于Kyle(1985)提出的资产交易简单微观基础模型,研究在何种条件下,一个私下了解资产未来回报的交易者可能希望与其他交易者分享她的信息。与传统观点相反,我们表明在博弈的唯一均衡中,知情交易者以正概率揭示她的信息。其结果是,与相应的无沟通基准相比,均衡价格不必完全揭示资产回报,即使交易者是风险中性的。这反过来对社会剩余的分配有重要影响。虽然我们的模型最初假设代理间的沟通受到任意给定的社交网络的限制,我们也研究了当链接通过交易者先前的连接决策内生形成时,会出现哪些这样的网络。
We build upon a simple micro-founded model of asset trading proposed by Kyle (1985) to study under what conditions a trader who is privately informed of the future return of the asset may want to share her information with other traders. Despite what conventional wisdom suggests, we show that in the unique equilibrium of the game the informed trader reveals her information with positive probability. A consequence of it is that, in contrast with the corresponding no-communication benchmark, the equilibrium price need not be fully revealing of the asset's return, even if traders are risk neutral. This, in turn, has significant implications on the distribution of the social surplus. While our model initially assumes that inter-agent communication is restricted by an arbitrarily given social network, we also study which such networks arise when links are endogenously formed through traders' prior connection decisions.
多消费者市场中个体需求的面板数据估计
Sarah Moon, Whitney K. Newey
AI总结 研究如何利用面板数据估计个体需求,通过差分等方法消除市场定价内生性偏差,发现当每个市场消费者数量增加时偏差消失,并允许宏观经济效应。
本文旨在考虑面板数据是否以及如何用于估计个体需求(而非市场层面需求),同时考虑由市场定价导致的同时性问题。我们考虑线性需求模型和随机系数需求模型,以及线性供给模型。我们发现,使用熟悉的的面板数据方法(如差分)获得的个体需求估计的偏差随着每个市场消费者数量的增加而消失,只要偏好的时变(即异质性)成分与供给的未观测时变成分正交。这种近似控制在许多面板离散选择模型中被假设,并且在其他模型中也是合理的,其中异质性偏好代表偏好随时间的随机变化。可以通过包含表征时间效应的回归量(如趋势和时间周期虚拟变量)或固定时间效应来允许宏观经济效应。
The purpose of this paper is to consider whether and how panel data can be used to estimate individual demand, as opposed to market-level demand, while accounting for simultaneity resulting from prices being determined in markets. We consider linear demand models and random coefficient demand models, together with linear supply models. We find that the bias of individual demand estimates obtained using familiar panel data methods, like differencing, disappears as the number of consumers in each market grows, as long as the time-varying, i.e. idiosyncratic, component of preferences is orthogonal to the unobserved, time-varying component of supply. This approximate control is assumed in many panel discrete choice models and is plausible in other models where idiosyncratic preferences represent random variation in preferences over time. Macroeconomic effects can be allowed for by including regressors characterizing time effects, such as trends and time period dummies, or fixed time effects.
再论一致概率社会选择
Florian Brandl, Felix Brandt
AI总结 将Brandt等人(2016)基于分数偏好概型的最大抽签结果转移到标准有限选民模型,并放宽连续性条件至实数概率。
Brandt等人(2016)在一个基于分数偏好概型的框架内刻画了一种称为最大抽签的概率社会选择函数,该框架抽象掉了个体选民。虽然这一建模假设使得证明更加优雅和透明,但它使得与文献中其他结果的比较变得复杂。本注记的目的是将他们的结果转移到社会选择的标准模型,其中每个偏好概型由有限数量的选民定义。在此过程中,我们证明了他们主要定理的一个稍强版本,该版本使用了更弱的连续性条件,并允许实数值(而不仅仅是理性值)概率。
Brandt et al. (2016) characterized a probabilistic social choice function known as maximal lotteries within a framework based on fractional preference profiles, which abstracts away from individual voters. While this modeling assumption enables a more elegant and transparent proof, it complicates comparison with other results in the literature. The purpose of this note is to transfer their results to the standard model of social choice, where each preference profile is defined for a finite number of voters. Along the way, we prove a slightly stronger version of their main theorem that uses a weaker continuity condition and allows for real-valued (rather than only rational-valued) probabilities.
迭代消除博达败者:鲍德温和南森规则的公理化
Leo Goto, Satoshi Nakada
AI总结 本文通过公理化方法统一刻画鲍德温和南森两种投票规则,其核心是递归消除博达得分最低或低于平均的选项,并与Young对博达规则的公理化进行对比。
鲍德温和南森规则是两种旨在识别孔多塞赢家(当存在时)的投票规则。两种规则都作为递归的博达消除程序运作:鲍德温规则连续消除博达得分最低的选项,而南森规则消除所有博达得分不超过平均值的选项。本文研究了鲍德温和南森规则的公理性质,并提供了统一的公理化刻画。特别地,我们的公理与Young(1974)对博达规则的公理化紧密可比。
The Baldwin and Nanson rules are two voting rules proposed to identify the Condorcet winner whenever one exists. Both rules operate as recursive Borda elimination procedures: the Baldwin rule successively eliminates the alternatives with the lowest Borda score, whereas the Nanson rule eliminates all alternatives whose Borda scores do not exceed the mean. This paper investigates the axiomatic properties of the Baldwin and Nanson rules and provides unified axiomatic characterizations. In particular, our axioms are closely comparable to Young's (1974) characterization of the Borda rule.
有限信念传播与权变思维
Andrew Ellis, Ran Spiegler
AI总结 本文通过有向无环图上的有限推理步骤,刻画了观察后信念更新的非贝叶斯特征,解释了相关忽视和迭代期望违背,并应用于公共品供给和社会学习博弈。
一个智能体在观察部分变量后更新其对一组变量的信念。我们提供了更新信念的一种表示,该表示捕捉了观察结果的含义通过表示所有变量之间关系的有向无环图进行有限传播。当她从未观察变量到观察变量进行的推理步骤较少时,就会发生权变思维的失败,导致相关忽视和迭代期望的违背。我们的框架为关于权变思维的现有实验提供了新视角,并提出了新的方向。我们刻画了该模型与熟悉的贝叶斯和非贝叶斯基准之间的关系,并通过公共品供给和社会学习博弈的应用加以说明。
An agent updates her beliefs over a set of variables after observing some of them. We provide a representation of updated beliefs that captures limited propagation of her observation's implications through the directed acyclic graph that represents the relations between all variables. Failure of contingent thinking occurs when she performs fewer inference steps from unobserved variables than observed ones, leading to correlation neglect and violations of iterated expectations. Our framework offers a new perspective on existing experiments about contingent thinking and suggests new directions. We characterize the model's relationship with familiar Bayesian and non-Bayesian benchmarks, and illustrate it with applications to public-good provision and social learning games.
带有规划的序贯搜索
Ruhi Sonal, Saptarshi Mukherjee, Abhinaba Lahiri, Aniruddha Ghosh
AI总结 本文通过有序潘多拉盒子模型研究新产品开发或资源勘探中的序贯搜索,引入规划成本,证明存在与已支付范围相关的保留值,并分析保证效应、已支付范围效应和剩余阶段效应对最优策略的影响。
新产品或技术的序贯开发,或自然资源的勘探,通常通过有序阶段进行,具有不确定的回报,并且需要昂贵的(事前)规划以使未来阶段可访问。我们将此过程建模为一个有序的潘多拉盒子问题,其中决策者首先选择一个初始范围,支付随可访问阶段数量增加的成本,并可能随后以边际调整成本扩大范围。由于已支付的规划成本是沉没的,续值取决于状态变量“已支付范围”。我们证明了与范围相关的保留值的存在性和唯一性,将最优搜索策略刻画为由已支付范围索引的阈值规则,并推导出比较静态。三种经济力量之间的相互作用塑造了最优行为——保证效应(更高的当前最佳报价降低了下一阶段的预期改进并导致更早停止)、已支付范围效应(更大的预付范围降低了未来访问的边际成本,提高了续值,并在更高保证下支持继续)以及剩余阶段效应(剩余阶段越少,继续的期权价值越小)。两个例子说明了这些力量如何在正态和厚尾回报下产生不同的规划和搜索模式。
Sequential development of a new product or technology, or natural resource exploration, often progresses through ordered stages with uncertain rewards and requires costly (ex ante) planning to make future stages accessible. We model this process as an ordered Pandora's box problem where a decision-maker first chooses an initial scope, paying a cost that rises with the number of stages made accessible, and may later expand the scope at a marginal adjustment cost. Since the paid planning costs are sunk, the continuation values depend on the state variable ``paid scope''. We prove existence and uniqueness of scope-dependent reservation values, characterize the optimal search strategy as a threshold rule indexed by paid scope, and derive comparative statics. Interactions among three economic forces shape the optimal behavior -- a guarantee effect (a higher current best offer reduces the expected improvement from the next stage and induces earlier stopping), a paid-scope effect (a larger prepaid scope lowers the marginal cost of future access, raises the continuation value, and supports continuation at higher guarantees), and a remaining-horizon effect (fewer stages remaining shrink the option value of continuing). Two examples illustrate how these forces generate distinct planning and search patterns under normal and fat-tailed rewards.
数据驱动的自动化
Maryam Farboodi, Andrew Koh, Anchi Xia
AI总结 本文构建了一个数据驱动的自动化动态模型,研究数据异质性、内生积累和溢出效应如何影响自动化进程,发现长期自动化速度遵循幂律衰减,且经济通常无效率。
我们构建了一个数据驱动的自动化动态模型,其中数据(i)是异质且任务特定的;(ii)作为经济活动的副产品内生积累;且(iii)表现出溢出效应,使得一个任务生成的数据可以增强另一个任务的生产率。在自动化的转型路径上,数据扮演着双重角色:同时增强已自动化任务的生产率并扩展自动化前沿。我们推导了经济长期部分自动化与完全自动化的严格条件。在后一种情况下,自动化表现出丰富的短期动态,取决于数据溢出的模式,但长期总是缓慢的:劳动力生产的任务份额随时间渐近地服从幂律衰减。我们表明经济通常是低效的,并分析规划者如何最优地倾斜数据积累的方向。在资本内生积累的情况下,数据驱动的自动化产生爆炸性增长,但长期工资停滞。
We build a dynamic model of data-driven automation in which data (i) is heterogeneous and task-specific; (ii) accumulates endogenously as a byproduct of economic activity; and (iii) exhibits spillovers such that data generated by one task can augment the productivity of another. Along the transition path of automation, data plays a dual role in simultaneously augmenting the productivity of already-automated tasks and expanding the automation frontier. We derive tight conditions for the economy to be partially versus fully automated in the long-run. In the latter case, automation exhibits rich short-run dynamics that depend on the pattern of data spillovers but is always slow in the long-run: the share of tasks produced by labor decays asymptotically as a power law in time. We show that the economy is generically inefficient and analyze how a planner optimally tilts the direction of data accumulation. With endogenous capital accumulation, data-driven automation generates explosive growth but stagnant long-run wages.
承诺与家庭劳动力供给的动态:来自欧洲的新检验与证据
Pierre-Andre Chiappori, Alexandros Theloudis, Jorge Velilla, Jose Ignacio Gimenez-Nadal, Jose Alberto Molina
AI总结 利用生命周期集体模型,基于工资冲击对家庭劳动力供给的动态影响,提出区分完全、有限和无承诺的新检验,并在15个欧洲国家实施,发现有限承诺普遍成立。
配偶对未来行为的承诺能力对资源在夫妻间及跨时期的分配具有重要意义。利用家庭行为的生命周期集体模型,我们基于工资冲击对家庭劳动力供给的动态影响,提出了区分完全承诺、有限承诺和无承诺的新检验。我们方法的一个新颖之处在于,除了其他两种类型外,它还能正式拒绝有限承诺,利用理论上的符号限制。我们使用2005-2019年欧盟收入与生活条件统计(EU-SILC)的数据,在15个欧洲国家实施了这些检验。我们发现,帕累托权重对有利的过去工资的弹性通常为正,这与有限承诺下的讨价还价一致。因此,过去的工资冲击会对劳动力供给产生讨价还价效应,增强受薪配偶的权力,削弱伴侣的权力。形式上,我们在除4个国家外的所有国家拒绝了完全承诺和无承诺,但未能拒绝有限承诺。
The ability of spouses to commit to future behavior has important implications for the allocation of resources between them and over time. Using a lifecycle collective model for household behavior, we propose new tests that distinguish between full, limited, and no commitment, based on the dynamic impact of wage shocks on household labor supply. A novelty of our approach is its ability to formally reject limited commitment, in addition to the other two types, exploiting sign restrictions from theory. We implement our tests across 15 European countries, drawing data from the EU-SILC over the years 2005-2019. We find that the elasticity of the Pareto weight with respect to favorable past wages is generally positive, consistent with bargaining under limited commitment. Past wage shocks thus induce bargaining effects on labor supply, empowering the recipient spouse and weakening the partner. Formally, we reject full and no commitment in all but 4 countries, but fail to reject limited commitment.
初学者引力模型导论
Luigi Capoani
AI总结 本文以教学方式介绍引力模型,从经典物理学到国际经济学的概念转换,强调经济质量(GDP)吸引贸易流而地理距离产生空间阻力,并梳理文献演变。
本文对引力模型及其从经典物理学到国际经济学的概念转换进行了教学性和初学者友好的综述。在简要介绍之后,首先建立了牛顿万有引力定律与经济引力方程之间的结构和数学平行关系,展示了经济质量(GDP)如何吸引贸易流,而地理距离则作为空间阻力的来源。然后,本文考察了将刚性自然法则应用于集体人类行为所需的确定性哲学框架。最后,追溯了文献的时间演变,强调了早期人口学家和Walter Isard发展的基于物理学的方法与后来出现的基于效用的计量经济学适应之间的历史分歧。本文最终表明,尽管全球化,空间摩擦仍然是塑造国际贸易和地缘政治互动的重要且可测量的力量。
This paper provides a didactic and beginner friendly review of the gravity model and its conceptual translation from classical physics into international economics. After a brief introduction, it begins by establishing the structural and mathematical parallels between Newton's law of universal gravitation and the economic gravity equation, demonstrating how economic mass (GDP) attracts trade flows while geographic distance acts as a source of spatial resistance. The paper then examines the deterministic philosophical framework required to apply rigid natural laws to collective human behavior. Finally, it traces the chronological evolution of the literature, highlighting the historical divergence between the physics rooted approach developed by early demographers and Walter Isard and the utility based econometric adaptations that later emerged. The paper ultimately shows that, despite globalization, spatial friction remains a significant and measurable force shaping international trade and geopolitical interactions.
美国技能专业化、关联性和复杂性的经济地理数据集
Anthony Howell, Maryann Feldman, Lauren Lanahan, Nikhil Kalathil, Evan Johnson
AI总结 基于2010-2024年4.336亿条职位发布,构建了覆盖3194个县的技能专业化、关联性、多样性和复杂性等经济地理变量,并分解至雇主实体类型。
我们发布了一个新的美国技能专业化、关联性和复杂性的数据集,该数据集源自2010年至2024年间的4.336亿条职位发布。该面板数据覆盖了15年间的3194个县,并报告了201个变量,这些变量描述了职位发布的数量(例如,劳动力需求)、工作的形式与性质(例如,远程工作比例、实习比例)以及按类别划分的雇主技能需求结构(例如,专业化、软件和通用技能)。我们开发了一套经济地理变量:基于技能的县专业化、关联性、多样性、复杂性和动态性指标。这些指标进一步按雇主实体类型(企业、大学、政府和联邦实验室)分解,并包含实体对的匹配度、重叠度和定向技能差距指标。一个配套的交互式仪表板支持学术研究和实际应用,其功能包括时空可视化、县排名与趋势、成对县比较以及单个县概况。
We release a new dataset of U.S. skill specialization, relatedness, and complexity, derived from 433.6 million job postings between 2010 and 2024. The panel covers 3,194 counties across 15 years and reports 201 variables that describe the volume of job postings (e.g., labor demand), the modality and nature of work (e.g., remote share, internship share), and the structure of employer skill demand by category (e.g., specialized, software, and common). We develop a suite of economic geography variables: skill-based measures of county specialization, relatedness, diversity, complexity, and dynamics. These measures are further decomposed by employer entity type (corporate, university, government, and federal lab), along with entity-pair measures of alignment, overlap, and directional skill gaps. An accompanying interactive dashboard supports both academic research and applied use, with features including spatiotemporal visualization, county rankings and trends, pairwise county comparisons, and individual county profiles.
从交易到记录:通过生命周期视角重新概念化区块链系统
Tom Barbereau, Ruggero Montalto, Christian Beyer
AI总结 本文引入ISO 15489-1:2016记录管理原则,提出区块链数据的七阶段生命周期模型,应用于比特币、同质化代币和非同质化代币,论证区块链系统不仅是交易基础设施,更是具有独特特征的记录管理系统。
当前的区块链研究和分析倾向于优先考虑可观察的链上交易,掩盖了加密货币创建、公开、保留和处置的过程。为此,本文从ISO 15489-1:2016的记录管理原则出发,考虑分布式账本技术。首先指定相似之处——即交易作为“记录”,加密资产单元作为“信息资产”,区块链作为“聚合”——我们引入了区块链数据的七阶段生命周期。我们将该框架应用于比特币、同质化代币和非同质化代币。在此基础上,我们认为区块链系统不仅仅是交易基础设施,而是具有独特特征的记录管理系统。我们讨论了链上/链下边界和隐私增强技术如何使生命周期可见性复杂化,这对加密犯罪研究和调查尤为重要。作为一个元级框架,生命周期视角能够定位现有研究,按阶段分解法律、监管、技术和运营挑战,并为区块链治理、分析和监管提供生命周期感知的方法。
Current blockchain research and analytics tend to prioritize observable on-chain transactions, obscuring the processes through which cryptocurrencies are created, publicised, retained, and disposed of. In response, this paper considers distributed ledger technologies from records management principles in ISO 15489-1:2016. Setting off by specifying the parallels -- that is transactions as "records", crypto-asset units as "information assets", and blockchains as "aggregations" -- we introduce a seven-stage lifecycle for blockchain data. We apply the framework to Bitcoin, a fungible token, and a non-fungible token. On this basis, we argue that blockchain systems are not merely transactional infrastructures but record management systems with distinctive characteristics. We discuss how the on-chain/off-chain boundary and privacy-enhancing technologies can complicate lifecycle visibility, with particular relevance for crypto-crime research and investigation. As a meta-level framework, the lifecycle perspective enables positioning existing research, decomposing legal, regulatory, technological, and operational challenges by stage, and informing lifecycle-aware approaches to blockchain governance, analytics, and regulation.
GAGI:一种用于分布感知宏观经济福利监测的基尼调整人均GDP指数
Sivasathivel Kandasamy
AI总结 提出GAGI指数,通过基尼系数和价格水平调整人均GDP,以监测福利分配效应,应用于G7国家发现福利增长与GDP增长持续偏离。
人均GDP是政府机构追踪经济繁荣和经济事件后果的默认视角,但它忽视了生活繁荣的两个首要决定因素:收入/财富分配和通胀影响。不平等调整的收入衡量指标本身并不新鲜,但宏观经济监测工具包中具体缺失的不是福利概念,而是一个可操作的监测触发指标:一个足够简洁、可每年从公开数据计算、无需建模假设即可审计、且标准化以便于理解年度间和国家间变化(监管机构需要据此采取行动)的统计量。我们构建了这样一个工具,即基尼调整人均GDP指数(GAGI):一种可复现、可公开计算的公式,通过不平等调整因子(1-G)和价格水平重新调整各国人均GDP,并以2010年为基准标准化。GAGI是一个通用福利指数,并非特定于AI自动化,适用于任何需要追踪福利调整后繁荣的场景。将GAGI应用于2010-2026年的G7经济体,我们发现福利调整后的繁荣与总体GDP增长持续且日益偏离,这种偏离在2022年后急剧扩大,时间上与COVID后遗症和生成式AI部署加速相吻合,尽管仅凭此证据尚不能证明因果关系。我们认为GAGI是基于GDP监测的必要补充:任何仅追踪总产出的宏观经济监测工具都会系统性地忽略自动化可能造成的分配损害,即使报告的增长依然强劲。
GDP per capita is the default lens through which governibng bodies track the economic prosperity and consequences of economic events , yet it is blind to two first-order determinants of lived prosperity: income/wealth distribution and inflation impact. Inequality-adjusted income measures are themselves not new but What is missing from the macroeconomic monitoring toolkit specifically is not a welfare concept but an operational monitoring trigger: a statistic minimal enough to compute annually from public data, transparent enough to audit without modelling assumptions, and normalised so that year-on-year, cross-country change ? the quantity a regulator needs to act on? is legible. We assemble such an instrument, the Gini- Adjusted GDP per Capita Index (GAGI): a reproducible, publicly computable formulation that rescales each country's GDP per capita by its inequality-adjustment factor (1-G) and its price level, normalised to a 2010 baseline. GAGI is a general-purpose welfare index, not inherently specific to AI automation, applicable wherever welfare-adjusted prosperity needs tracking. Applying GAGI to the G7 economies over 2010-2026, we show that welfare-adjusted prosperity has diverged persistently and increasingly from headline GDP growth, that the divergence widens sharply after 2022, temporally coincident with, though not, on this evidence alone, demonstrated to be caused by the after effects of COVID and the acceleration of generative-AI deployment. We argue that GAGI is a necessary complement to GDP-based monitoring: any macroeconomic monitoring instrument that tracks only aggregate output will systematically miss the distributional harm that automation can cause even while reported growth remains strong.
从堆栈到电路:行星边界内人工智能基础设施的再生社会技术路线图
Han-Teng Liao, Karen Ang
AI总结 针对生成式AI线性扩展导致的热力学和材料成本外部化问题,提出一种再生社会技术路线图,通过代谢电路框架将AI基础设施重塑为受行星边界约束的系统之系统,并识别当前以Nvidia为中心的路线图的空白,提出竞争性参考架构。
当前生成式AI的扩展轨迹,以线性供给侧“堆栈”为典型,优先考虑性能密度,同时将显著的热力学和材料成本外部化。随着绿色与数字转型的“双重转型”加速,行业面临技术差距——包括范围3排放和电子废物回收——这些差距阻碍了可持续扩展并导致社会紧张。本研究提出了一种再生社会技术路线图,重新利用可持续生产与消费系统图,将人工智能基础设施重塑为最终受行星边界约束的系统之系统。通过整合电气和电子工程师协会国际器件与系统路线图(IEEE IRDS)对半导体设施的可持续性考量,本研究提出了一种代谢电路框架,将“价值观与需求”置于生产与消费关系循环的中心。本研究识别了当前以Nvidia为中心的路线图中的关键空白,并提出了一种竞争性参考架构。它展示了资源节约和行星责任的自发秩序如何为数字循环经济中的监管合规和产业韧性提供可行的路径。
Current scaling trajectories for Generative AI, typified by linear supply-side "stacks," prioritize performance density while externalizing significant thermodynamic and material costs. As the "Twin Transition" of green and digital transformation accelerates, the industry faces technology gaps - including Scope 3 emissions and e-waste recycling - that impede sustainable scaling and lead to social tensions. This study proposes a Regenerative Socio-Technical roadmap that repurposes the Sustainable Production and Consumption system map to reframe artificial intelligence infrastructure as a system-of-systems governed ultimately by planetary limits. By integrating the Institute of Electrical and Electronics Engineers International Roadmap for Devices and Systems (IEEE IRDS) sustainability considerations for semiconductor facilities, the study proposes a metabolic circuit framework that centers "Values and Needs" within production and consumption relationship loops. This study identifies critical gaps in current Nvidia-centric roadmaps and proposes a competing reference architecture. It demonstrates how a spontaneous order of resource parsimony and planetary accountability can provide an actionable pathway for regulatory compliance and industrial resilience in the digital circular economy.
最优多物品多竞拍者拍卖设计的对偶性:通过深度学习的收入证书
Yanchen Jiang, David C. Parkes, Tonghan Wang
AI总结 提出首个直接处理多物品多竞拍者拍卖对偶问题的计算框架,通过神经网络参数化拉格朗日乘子并引入提升技术,生成可证明的收入上界,为连续类型提供近最优性证书。
刻画多物品、多竞拍者设置下的收入最优拍卖仍然是一个基本开放问题,除了限制性的二元类型实例外,没有已知的闭式解。这激发了人们对最优拍卖设计的计算方法的兴趣。在本文中,我们引入了第一个直接处理多物品、多竞拍者拍卖和占优策略激励相容(DSIC)的对偶问题的计算框架,生成有证书的收入上界。我们的方法使用神经网络参数化具有结构保证的严格流量守恒性质的拉格朗日乘子,从而通过梯度下降对可行对偶解进行高效优化。为了弥合离散计算方法与连续类型的理论保证之间的差距,我们开发了一种新颖的提升技术,将对偶证书从粗离散化映射到精细细化。我们证明,对于具有连续均匀估值的多物品、多竞拍者拍卖,提升给出了有效的收入上界。此外,我们给出了任意连续分布的广义提升构造,并证明了这些提升对偶在离散极限下收敛到原始连续问题的收入。我们通过恢复典型实例的已知分析机制,验证了该对偶拍卖设计问题的计算框架。对于多物品多竞拍者问题,我们的框架在最优收入与已知最佳DSIC机制之间建立了小差距,提供了近最优性的计算证书。
Characterizing revenue-optimal auctions for multi-item, multi-bidder settings remains a fundamental open problem, with no known closed-form solution existing beyond restrictive binary-type instances. This has motivated interest in computational approaches to optimal auction design. In this paper, we introduce the first computational framework that directly tackles the dual problem for multi-item, multi-bidder auctions and dominant-strategy incentive compatibility (DSIC), generating certified revenue upper bounds. Our approach parametrizes Lagrange multipliers with a structurally guaranteed strict flow-conservation property using neural networks, enabling efficient optimization over feasible dual solutions via gradient descent. To bridge the gap between discrete computational methods and theoretical guarantees for continuous types, we develop a novel lifting technique that maps dual certificates from coarse discretizations to fine refinements. We prove that lifting gives valid revenue upper bounds for multi-item, multi-bidder auctions with continuous uniform valuations. Furthermore, we give a generalized lifting construction for arbitrary continuous distributions and demonstrate that these lifted duals converge to the revenue of the original continuous problem in the discrete limit. We validate this computational framework for the dual auction design problem by recovering known analytical mechanisms for canonical instances. For multi-item multi-bidder problems, our framework establishes a small gap between the optimal revenue and best-known DSIC mechanisms, providing computational certificates of near-optimality.
组合风险下的决策
Yifan Hong, Hongmiao Fan, Chen Wang
AI总结 通过投资分配任务研究组合风险下的决策,发现参与者主要依据投资后成功概率等特征而非精确评估完整分布,并利用符号回归发现简洁描述模型。
风险下的决策通常通过单次彩票选择来研究。然而,许多实际决策涉及组合风险,其中风险来自多个风险组件,因此结果上的彩票是诱导的而非直接给出的,并且精确评估可能代价高昂。我们引入了一项投资分配任务来研究组合风险下的决策,其中投资于一个组件会提高其成功概率,从而重塑结果分布。参与者倾向于选择概率增量较大的选项,当增量相等时,选择初始成功概率较高的选项。揭示诱导的概率质量函数(PMF)会显著改变行为,使参与者对组合风险特征的反应减弱,并减少选择方差。为了解释这些模式,我们超越标准基准和手工假设,使用符号回归发现简洁的描述模型。发现的模型主要依赖于组合风险特征,例如投资后的成功概率,而不是对完整诱导分布的精确评估。当显示PMF时,行为可以通过用前景理论残差模型增强该模型来很好地解释。结果表明,人们主要通过核心特征来导航组合风险,仅在显示诱导PMF时才转向彩票估值。
Decision-making under risk is typically studied through single-shot lottery choices. Yet many real decisions involve combinatorial risk, where risk arises from multiple risky components, so the lottery over outcomes is induced rather than given outright and can be costly to evaluate exactly. We introduce an investment-allocation task to study decision under combinatorial risk, where investing in a component raises its success probability and thereby reshapes the outcome distribution. Participants favor the option with the larger probability increment, and, when increments are equal, the option with the higher initial success probability. Revealing the induced probability mass function (PMF) substantially changes behavior, making participants less responsive to combinatorial-risk features and reducing choice variance. To explain these patterns, we move beyond standard benchmarks and hand-crafted hypotheses with symbolic regression to discover compact descriptive models. The discovered models rely mainly on combinatorial-risk features, such as the after-investment success probability, rather than exact evaluation of the full induced distribution. Behavior under the displayed PMF is then well explained by augmenting this model with a prospect-theoretic residual model. The results show that people navigate combinatorial risk primarily through its core features, shifting toward lottery valuation only when the induced PMF is displayed.
深度多智能体强化学习在异步定价中的失败模式:可复现触发器、轨迹诊断及部分修复
Shree Murthy, Rohan Pandey
AI总结 研究连续时间定价市场中深度多智能体强化学习的两种可复现失败模式:DDPG智能体之间的默契合谋和高事件率下的演员-评论家不稳定性,并通过异步性实现部分修复。
我们研究了连续时间定价市场中深度多智能体强化学习的两种可复现失败模式:(i) 竞争性DDPG智能体之间形成默契合谋,以及(ii) 高事件率下的演员-评论家不稳定性。我们在一个单一的CT-MARL基准测试(泊松时钟价格更新、观测延迟$\delta$、内部最优logit需求)中实例化了这两种模式,表明同步DDPG智能体可靠地触发失败模式1,合谋指数$\Delta = 0.69 \pm 0.11$,并量化了一种部分微观结构修复:仅异步性就将合谋降低了48%,而增加延迟使其降至最低$\Delta = 0.28$。该修复具有明确记录的成本:它是部分的($\Delta$仍高于伯特兰水平),在$\delta$上非单调,并且无法承受失败模式2,后者在$\lambda = 5$时表现为DDPG评论家发散,并破坏了$(\lambda{=}5, \delta{=}1)$处的相图单元。我们为标量合谋指数配备了轨迹级诊断,揭示了情节内信号崩溃和冲击后无法恢复。
We study two reproducible failure modes of deep multi-agent reinforcement learning in continuous-time pricing markets: (i) tacit cartel formation between competing DDPG agents, and (ii) actor--critic instability at high event rates. We instantiate both inside a single CT-MARL benchmark (Poisson-clocked price updates, observation latency $δ$, interior-optimum logit demand), show that synchronous DDPG agents reliably trigger Failure Mode 1 with collusion index $Δ= 0.69 \pm 0.11$, and quantify a partial microstructure fix: asynchrony alone cuts collusion by 48\% and adding latency drives it to a minimum of $Δ= 0.28$. The fix has clearly documented costs: it is partial ($Δ$ remains supra-Bertrand), it is non-monotone in $δ$, and it does not survive Failure Mode 2, which emerges as DDPG critic divergence at $λ= 5$ and corrupts the phase-diagram cell at $(λ{=}5, δ{=}1)$. We accompany the scalar collusion index with trajectory-level trace diagnostics that expose the within-episode signalling collapse and the post-shock non-recovery.
推荐系统干预的非预期后果:来自现场实验的证据
Shilei Luo, Song Yao, Dennis J. Zhang
AI总结 通过短视频平台现场实验发现,睡眠提醒干预反而增加深夜使用14.75%和总使用2.18%,原因在于干预揭示了高潜在需求,触发推荐策略更新,形成持久性系统级影响。
推荐系统中的平台内容干预通常被评估为静态“助推”,忽略了系统会从用户行为中自适应学习。我们通过短视频平台的大规模现场实验研究了这一动态。实验涉及一项旨在减少深夜使用的“睡眠提醒”活动。矛盾的是,干预使深夜参与度增加了14.75%,整体平台使用增加了2.18%,并且这种影响在实验结束后持续了数周。我们通过强制探索机制解释这一现象,表明干预通过揭示推广内容的高潜在需求,触发了常规用户行为不会产生的推荐策略更新。干预产生的数据促使算法更新其活动后策略,强化了活动本意要缓解的参与循环。我们的发现表明,面向用户的干预可以有效重新训练底层算法,引发内容分发的持久性系统级变化,这对平台治理和社会责任倡议中的标准评估指标提出了挑战。
Platform content interventions in recommendation systems are typically evaluated as static "nudges", ignoring that the systems adaptively learn from the resulting user behavior. We investigate this dynamic through a large-scale field experiment on a short-video platform. The experiment involves a "sleep reminder" campaign designed to reduce late-night usage. Paradoxically, the intervention increased late-night engagement by 14.75% and overall platform usage by 2.18%, and the effects persisted for weeks even after the experiment. We explain this through a forced-exploration mechanism, showing that by revealing high latent demand for the promoted content, the intervention triggers a recommendation policy update that routine user behavior would not produce. The data generated by the intervention induced the algorithm to update its post-campaign policy, reinforcing the very engagement loops the campaign aimed to mitigate. Our findings demonstrate that user-facing interventions can effectively retrain the underlying algorithm, triggering durable, system-wide shifts in content distribution that challenge standard evaluation metrics in platform governance and social responsibility initiatives.
基于区块链的金融基础设施中真实世界资产代币化的分类法
Giorgio Vella, Luca Pennella, Mark C. Ballandies
AI总结 提出系统级分类法,从治理、资产结构、代币属性、分布式账本技术和经济五个维度分类真实世界资产代币化,并应用于20个主要系统,揭示混合架构和文档缺口。
真实世界资产(RWA)代币化已成为区块链技术的重要应用,使链外金融和非金融资产能够通过基于区块链的工具表示。然而,已部署的RWA系统仍然难以比较,因为法律主张、托管安排、代币机制、验证过程和链上集成通常被分开描述。本文开发了一个系统级的RWA代币化分类法,以分类链外资产如何在法律、经济和技术上在链上表示。遵循迭代分类法开发方法,我们将23个维度组织成五个组成部分:治理、资产结构、代币属性、分布式账本技术和经济。我们将分类法应用于按市值选择的20个主要RWA系统,并比较它们跨资产类别和实施模型的设计选择。分类显示,当前RWA代币化主要通过混合架构实现:区块链代币支持表示、转移控制、赎回工作流、定价和可组合性,而核心法律保证仍锚定在链外法律包装、托管安排、合规流程和验证机制中。分析还揭示了关于投票权、争议论坛、销毁机制、供应约束和储备验证的重复性文档缺口。总体而言,该分类法为比较RWA系统、识别设计模式和局限性以及支持未来关于基于区块链的金融基础设施的研究提供了结构化基础。
Real-world asset (RWA) tokenization has emerged as a prominent application of blockchain technology, enabling off-chain financial and non-financial assets to be represented through blockchain-based instruments. However, deployed RWA systems remain difficult to compare because legal claims, custody arrangements, token mechanics, verification processes, and on-chain integrations are often described separately. This paper develops a systems-level taxonomy of RWA tokenization to classify how off-chain assets are legally, economically, and technically represented on-chain. Following an iterative taxonomy-development method, we organize twenty-three dimensions into five components: governance, asset structure, token properties, distributed ledger technology, and economy. We apply the taxonomy to twenty major RWA systems selected by market capitalization and compare their design choices across asset classes and implementation models. The classification shows that current RWA tokenization is predominantly implemented through hybrid architectures: blockchain tokens support representation, transfer control, redemption workflows, pricing, and composability, while core legal guarantees remain anchored in off-chain legal wrappers, custodial arrangements, compliance processes, and verification mechanisms. The analysis also reveals recurring documentation gaps concerning voting rights, dispute forums, burn mechanics, supply constraints, and reserve verification. Overall, the taxonomy provides a structured basis for comparing RWA systems, identifying design patterns and limitations, and supporting future research on blockchain-based financial infrastructure.
学会匹配:具有时间扩展反馈的双边匹配
Haijing Zong, Yancheng Liang, Boyang Zhou, Natasha Jaques
发表机构 * University of Washington
AI总结 提出一个具有时间扩展反馈的双边匹配框架,将其建模为部分可观测马尔可夫博弈,并基于多智能体强化学习构建Learn2Match基准,实验表明独立PPO优于bandit基线,但存在信息摩擦损失。
双边匹配市场通常涉及随时间通过面试、重复互动、学习和分离而展开的信息。现有的匹配模型通常将此过程简化为关于固定偏好的即时亚高斯反馈,忽略了支付相关信息逐渐揭示并改变未来匹配决策的场景。我们引入了一个具有时间扩展反馈的框架,将双边匹配建模为一个部分可观测马尔可夫博弈,其中包含昂贵的匹配前筛选、有噪声的匹配后观测、演变的潜在特征以及内生的延续或解散。我们在Learn2Match中实例化该框架,这是一个用于动态匹配市场的多智能体强化学习基准。Learn2Match支持关于面试谁、与谁匹配以及何时解散匹配的分散决策,同时使用遗憾、社会福利和信息摩擦损失(衡量由潜在偏好不完全揭示引起的福利差距)来评估策略。我们发现,在时间扩展反馈下,独立PPO比bandit风格的CA-ETC基线实现了更高的累积社会福利和更低的累积遗憾,展示了MARL在动态匹配市场中的前景。然而,PPO仍然产生更高的信息摩擦损失,表明端到端MARL尚未提供匹配bandit方法的协调探索结构。这些结果将Learn2Match定位为开发下一代匹配市场算法的基准:像RL智能体一样自适应、像bandit算法一样统计严谨、像稳定匹配机制一样结构感知的方法。
Two-sided matching markets often involve information that unfolds over time through interviews, repeated interaction, learning, and separation. Existing matching models typically reduce this process to immediate sub-Gaussian feedback about fixed preferences, missing settings where payoff-relevant information is revealed gradually and changes future matching decisions. We introduce a framework with temporally extended feedback, that formulates two-sided matching as a partially observable Markov game with costly pre-match screening, noisy post-match observations, evolving latent profiles, and endogenous continuation or dissolution. We instantiate this framework in Learn2Match, a multi-agent reinforcement-learning benchmark for dynamic matching markets. Learn2Match supports decentralized decision making over whom to interview, whom to match with, and when to dissolve a match, while evaluating policies using regret, social welfare, and an information-friction loss that measures the welfare gap caused by incomplete revelation of latent preferences. We find that independent PPO achieves higher cumulative social welfare and lower cumulative regret than the bandit-style CA-ETC baseline under temporally extended feedback, demonstrating the promise of MARL for dynamic matching markets. However, PPO still incurs higher information-friction loss, revealing that end-to-end MARL does not yet provide the coordinated exploration structure of matching-bandit methods. These results position Learn2Match as a benchmark for developing the next generation of matching-market algorithms: methods that are adaptive like RL agents, statistically disciplined like bandit algorithms, and structurally aware like stable-matching mechanisms. Please refer to https://sites.google.com/view/learn-to-match/home for the official website and the code link.
无转移支付下的目标定位
Filip Tokarski
AI总结 研究禁止货币转移时异质商品的福利最大化分配,通过机制设计刻画最优分配方案,并证明在特定条件下可通过简单菜单实现。
我研究了当禁止货币转移时,异质商品的福利最大化分配。代理人拥有私人价值,设计者选择满足激励相容和总供给约束的机制。我刻画了两种商品的最优机制,并表明该机制要么为每种商品提供一个纯选项,要么增加一个提供更大总量的捆绑包。当商品之间的狭窄偏好边际足以预测更大需求时,包含捆绑包是最优的,这使得设计者能够通过代理人接受混合的意愿来瞄准高价值代理人。然后,我考虑了N种商品的情况,并刻画了最优机制何时采取简单菜单的形式,其中每个选项提供某种商品的一定数量而不提供其他商品。在这种情况下,它可以通过具有平等收入的竞争均衡或基于选择的抽签来实施。
I study the welfare-maximizing allocation of heterogeneous goods when monetary transfers are prohibited. Agents have private values, and the designer chooses a mechanism subject to incentive compatibility and aggregate supply constraints. I characterize the optimal mechanism for two kinds of goods, and show that it either offers one pure option per good or adds a bundle that delivers a larger total quantity. Including the bundle is optimal when narrow preference margins between goods are sufficiently predictive of greater need, allowing the designer to target high-value agents through their willingness to accept mixing. I then consider the case with N types of goods and characterize when the optimal mechanism takes the form of a simple menu, where each option offers some amount of one kind of good and none of the others. When this is the case, it can be implemented as a competitive equilibrium with equal incomes or a choice-based lottery.
动态机制坍塌:边界刻画
Xiaopeng Zeng, Erbao Cao
AI总结 研究单次资源动态机制设计中,公共历史超越后验信念影响卖方事前价值的条件,通过信念空间支付映射和有限凹化刻画最优价值,给出后验信念充分性的边界准则。
公共历史可能改变延续规则,但不改变事前价值。我们研究在单次资源的动态机制设计中,何时超越后验信念的公共历史会影响卖方的事前价值。我们从由日期和后验信念索引的最大序贯均衡延续值构建了一个信念空间支付映射。我们证明动态问题的最优事前价值是这些延续值的上包络的有限凹化。我们给出了一个信念空间准则,用于判断何时非后验公共历史没有额外价值,从而一个终端仅后验机制可以达到全历史价值。我们的结果为公共历史何时影响事前价值(而不仅仅是影响延续博弈)提供了结构性洞见。
Public histories may change continuation rules but not ex-ante value. We study when public histories beyond posterior beliefs affect the seller's ex-ante value in dynamic mechanism design with a single-shot resource. We construct a belief-space payoff map from maximal sequential-equilibrium continuation values indexed by date and posterior belief. We show that the optimal ex-ante value of the dynamic problem is the finite concavification of the upper envelope of these continuation values. We give a belief-space criterion for when non-posterior public histories have no additional value, so that a terminal posterior-only mechanism attains the full-history value. Our results provide structural insights into when public histories matter for ex-ante value rather than merely for continuation play.
通过正则化最优传输进行部分识别矩模型的推断
Grigory Franguridi, Laura Liu
AI总结 提出基于正则化最优传输的部分识别GMM模型推断方法,用熵正则化近似支撑函数并利用Sinkhorn算法高效计算,建立熵正则化OT的CLT,通过bootstrap获得有效临界值,在蒙特卡洛模拟和幸福度面板logit模型中验证性能。
许多统计和计量经济学问题涉及由联合分布的矩定义的参数,但仅观测到边际分布,这自然导致部分识别。我们开发了一种用于相应部分识别GMM模型的识别、估计和推断方法。我们通过支撑函数/最优传输(OT)表示来刻画感兴趣参数的尖锐识别集。为了估计识别集,我们采用熵正则化,它提供了经典OT问题的光滑近似,可以使用Sinkhorn算法高效计算。我们还提出了用于假设检验和构建识别集置信区域的检验统计量。为了推导其渐近分布,我们建立了在一般光滑成本函数下熵正则化OT值的新中心极限定理。然后,我们使用Fang和Santos(2019)的方向可微泛函的bootstrap获得有效临界值。所得检验过程在局部均匀地控制大小,包括在识别集边界上的参数值处。我们在蒙特卡洛模拟中展示了我们方法的良好有限样本性能。最后,作为实证说明,我们使用来自“理解美国研究”的数据,估计了一个带有流失和补充的自报幸福度的面板logit模型。
Many statistical and econometric problems involve parameters defined by moments of a joint distribution when only marginal distributions are observed, leading naturally to partial identification. We develop a methodology for identification, estimation, and inference in the corresponding partially identified GMM model. We characterize the sharp identified set for the parameter of interest via a support-function/optimal-transport (OT) representation. To estimate the identified set, we employ entropic regularization, which yields a smooth approximation to the classical OT problem that can be computed efficiently using the Sinkhorn algorithm. We also propose a test statistic for hypothesis testing and the construction of confidence regions for the identified set. To derive its asymptotic distribution, we establish a novel central limit theorem for the entropic OT value under general smooth cost functions. We then obtain valid critical values using the bootstrap for directionally differentiable functionals of Fang and Santos (2019). The resulting testing procedure controls size locally uniformly, including at parameter values on the boundary of the identified set. We demonstrate good finite-sample performance of our methodology in Monte Carlo simulations. Finally, as an empirical illustration, we estimate a panel logit model of self-reported happiness with attrition and refreshment, using data from the Understanding America Study.
测量不可测量之物?主观调查数据中尺度转换的系统性证据
Caspar Kaiser, Anthony Lepinteur
AI总结 本文通过实验和大量复制研究,量化主观调查中顺序响应尺度的非线性程度,发现系数符号和显著性稳健,但相对幅度受非线性影响显著。
顺序响应尺度在经济学中无处不在,但其解释依赖于一个未经检验的假设:数字标签反映相等的心理间隔。我们开发了一个框架来量化放松这一假设对实证结果的影响。利用新的实验证据,我们表明尺度使用仅轻微非线性。复制了来自80多篇论文的超过40,000个估计值,我们发现系数符号和显著性在很大程度上是稳健的,但相对幅度则不然。即使是适度的非线性也会在隐含的权衡中产生显著变化。
Ordered response scales are ubiquitous in economics, but their interpretation rests on an untested assumption: that numerical labels reflect equal psychological intervals. We develop a framework to quantify how relaxing this assumption affects empirical results. Using new experimental evidence, we show that scale use is only mildly non-linear. Replicating over 40,000 estimates from more than 80 papers, we find that coefficient signs and significance are largely robust, but relative magnitudes are not. Even modest non-linearities generate substantial variation in implied trade-offs.
一种增强贝叶斯VAR与非线性因子的灵活方法
Todd Clark, Florian Huber, Gary Koop
AI总结 本文提出一种用回归树非参数建模非线性因子的向量自回归模型,通过因子方法简洁建模非线性,避免误设,实现高效贝叶斯计算,并适用于结构冲击识别。
本文提出了一种向量自回归模型,该模型通过回归树非参数地建模非线性因子。我们的模型有四个主要优点。第一,因子方法的使用确保了非线性偏离被简洁地建模。特别是,它们表现出功能池化,即使用少量非线性因子来建模变量间的共同非线性。第二,非参数地建模潜在非线性降低了误设的风险。第三,即使在非常高维的模型中,使用MCMC的贝叶斯计算也是直接的,允许高效的逐方程估计,从而避免了诸如时变参数VAR等流行替代方法中出现的计算瓶颈。第四,现有的线性因子模型中识别结构性经济冲击的方法可以通过我们的模型直接适用于非线性情况。涉及人工数据和宏观经济数据的实验说明了我们模型的性质及其在预测和结构性经济分析中的有用性。
This paper proposes a vector autoregression augmented with nonlinear factors that are modeled nonparametrically using regression trees. There are four main advantages of our model. First, the use of factor methods ensures that departures from linearity are modeled parsimoniously. In particular, they exhibit functional pooling where a small number of nonlinear factors are used to model common nonlinearities across variables. Second, modeling potential nonlinearities nonparametrically lessens the risk of misspecification. Third, Bayesian computation using MCMC is straightforward even in very high-dimensional models, allowing for efficient, equation-by-equation estimation, thus avoiding computational bottlenecks that arise in popular alternatives such as the time-varying parameter VAR. Fourth, existing methods for identifying structural economic shocks in linear factor models can be adapted for the nonlinear case in a straightforward fashion using our model. Exercises involving artificial and macroeconomic data illustrate the properties of our model and its usefulness for forecasting and structural economic analysis.
高维矩阵值时间序列的贝叶斯动态因子模型
Joshua C. C. Chan, Wei Zhang
AI总结 提出贝叶斯动态因子模型处理矩阵值时间序列,利用矩阵结构实现高维可处理性,并通过交叉熵重要性采样估计边际似然进行模型选择,在OECD宏观面板数据中优于静态矩阵因子基准。
我们引入了一类用于矩阵值时间序列的贝叶斯动态因子模型,具有自回归因子动态和异质成分,允许随机波动、异常值以及捕获跨行和跨列相关性的Kronecker结构协方差。利用矩阵结构,我们使这些参数丰富的模型在高维中可处理,并开发了高效的Gibbs采样器进行估计。对于模型比较,我们提出了一种基于边际似然的交叉熵重要性采样估计的统一方法,该方法在共同准则下选择因子维度、向量与矩阵结构以及异质规范。蒙特卡洛实验证实该估计量可靠地恢复了真实模型。在应用于包含190个时间序列的OECD宏观经济面板时,数据支持横截面相关性和随机波动性,并且该模型在样本外预测中比静态矩阵因子基准具有统计显著的改进。
We introduce a class of Bayesian dynamic factor models for matrix-valued time series, with autoregressive factor dynamics and idiosyncratic components that allow stochastic volatility, outliers, and a Kronecker-structured covariance capturing cross-row and cross-column correlation. Exploiting the matrix structure, we make these richly parameterized models tractable in high dimensions and develop an efficient Gibbs sampler for estimation. For model comparison, we propose a unified approach based on the cross-entropy importance-sampling estimator of the marginal likelihood, which under a common criterion selects the factor dimension, a vector versus matrix structure, and the idiosyncratic specification. Monte Carlo experiments confirm that the estimator reliably recovers the true model. In an application to an OECD macroeconomic panel of 190 time series, the data favor both cross-sectional correlation and stochastic volatility, and the model delivers statistically significant out-of-sample forecast gains over a static matrix factor benchmark.
基于大型语言模型的搜索引擎对抗攻击动力学
Xiyang Hu
AI总结 本文将排名操纵攻击建模为无限重复囚徒困境,分析合作维持条件,发现降低攻击成功率可能反而激励攻击,防御措施在某些情况下无效。
基于大型语言模型(LLM)的搜索引擎日益集成,改变了信息检索的格局。然而,这些系统容易受到对抗攻击,尤其是排名操纵攻击,攻击者通过精心制作网页内容来操纵LLM的排名并推广特定内容,从而在竞争对手中获得不公平优势。在本文中,我们研究了排名操纵攻击的动力学。我们将此问题建模为无限重复囚徒困境,其中多个参与者策略性地决定合作还是攻击。我们分析了合作得以维持的条件,识别了关键因素,如攻击成本、折现率、攻击成功率和触发策略,这些因素影响参与者的行为。我们识别了系统动力学中的临界点,表明当参与者具有前瞻性时,合作更有可能维持。然而,从防御角度来看,我们发现简单地降低攻击成功概率,在某些条件下反而会激励攻击。此外,限制攻击成功率上限的防御措施在某些情况下可能徒劳无功。这些见解凸显了保护基于LLM的系统的复杂性。我们的工作为理解和缓解其脆弱性提供了理论基础和实践见解,同时强调了自适应安全策略和深思熟虑的生态系统设计的重要性。
The increasing integration of Large Language Model (LLM) based search engines has transformed the landscape of information retrieval. However, these systems are vulnerable to adversarial attacks, especially ranking manipulation attacks, where attackers craft webpage content to manipulate the LLM's ranking and promote specific content, gaining an unfair advantage over competitors. In this paper, we study the dynamics of ranking manipulation attacks. We frame this problem as an Infinitely Repeated Prisoners' Dilemma, where multiple players strategically decide whether to cooperate or attack. We analyze the conditions under which cooperation can be sustained, identifying key factors such as attack costs, discount rates, attack success rates, and trigger strategies that influence player behavior. We identify tipping points in the system dynamics, demonstrating that cooperation is more likely to be sustained when players are forward-looking. However, from a defense perspective, we find that simply reducing attack success probabilities can, paradoxically, incentivize attacks under certain conditions. Furthermore, defensive measures to cap the upper bound of attack success rates may prove futile in some scenarios. These insights highlight the complexity of securing LLM-based systems. Our work provides a theoretical foundation and practical insights for understanding and mitigating their vulnerabilities, while emphasizing the importance of adaptive security strategies and thoughtful ecosystem design.
碳社会成本的Weitzman溢价
Jinchi Dong, Richard S. J. Tol, Fangzhi Wang
AI总结 偏好异质性大幅提高碳社会成本,称为Weitzman溢价。通过校准79,273人的时间偏好参数,发现平均碳社会成本是基准情形的6倍,敏感性分析中高达200倍。
偏好异质性大幅提高了碳社会成本。我们称之为Weitzman溢价。指数贴现率的不确定性意味着双曲贴现率,在短期内等于平均贴现率,但在长期内降至最低贴现率。我们将Weitzman(2001, AER)的伽马贴现推广到零通胀和两个维度,但发现解析解对非参数异质性的近似效果较差。我们校准了来自76个国家的79,273个人的纯时间偏好率和跨期替代弹性的倒数,并计算相应的碳社会成本。与平均时间偏好的碳社会成本相比,基准校准中的平均碳社会成本是其6倍,在敏感性分析中高达200倍。
Preference heterogeneity massively increases the social cost of carbon. We call this the Weitzman premium. Uncertainty about an exponential discount rate implies a hyperbolic discount rate, which in the near term is equal to the average discount rate but in the long term falls to the minimum discount rate. We generalise Weitzman's (2001, AER) gamma discounting to zero-inflation and two dimensions but find that the analytical solution is a poor approximation of the non-parametric heterogeneity. We calibrate the pure rate of time preference and the inverse of the elasticity of intertemporal substitution of 79,273 individuals from 76 countries and compute the corresponding social cost of carbon. Compared to the social cost of carbon for average time preferences, the average social cost of carbon is 6 times as large in the base calibration, and up to 200 times as large in sensitivity analyses.