【顶刊速递】Review of Economic Studies 《经济研究评论》：2025年1月期刊目录及摘要

注：中文摘要为机翻内容，未完全校对。

文章目录

1. 1.Labour Market Screening and the Design of Social Insurance: An Equilibrium Analysis of the Labour Market for the Disabled
   劳动力市场筛选与社会保险设计：对残疾人劳动力市场的均衡分析
   Naoki Aizawa, Soojin Kim, Serena Rhee
2. 2. Optimal Allocation via Waitlists: Simplicity Through Information Design
   通过候补名单进行最优分配：信息设计的简单实现
   Itai Ashlagi, Faidra Monachou, Afshin Nikzad
3. 3 Inefficient Automation
   低效的自动化
   Martin Beraja, Nathan Zorzi
4. 4.Migration and the Value of Social Networks
   移民与社会网络的价值
   Joshua E Blumenstock, Guanghua Chi, Xu Tan
5. 5.Private Sector Provision as an “Escape Valve”: The Mexico Diabetes Experiment
   私营部门提供作为“减压阀”：墨西哥糖尿病实验
   Ari Bronsoler, Jonathan Gruber, Enrique Seira
6. 6. Adaptive Estimation and Uniform Confidence Bands for Nonparametric Structural Functions and Elasticities
   非参数结构函数和弹性的自适应估计与均匀置信带
   Xiaohong Chen, Timothy Christensen, Sid Kankanala
7. 7.Information Spillovers and Sovereign Debt: Theory Meets the Eurozone Crisis
   信息溢出与主权债务：理论与欧元区危机
   Harold L Cole, Daniel Neuhann, Guillermo Ordoñez
8. 8. Partially Linear Models under Data Combination
   数据组合下的偏线性模型
   X D’Haultfœuille, C Gaillac, A Maurel
9. 9. Too Domestic to Fail: Liquidity Provision and National Champions
   太“国内”而不能倒闭：跨国企业的全球性与国家性
   Emmanuel Farhi, Jean Tirole
10. 10.The Climate in Climate Economics
    气候经济学中的气候
    Doris Folini, Aleksandra Friedl, Felix Kübler, Simon Scheidegger
11. 11. Good Politicians: Experimental Evidence on Motivations for Political Candidacy and Government Performance
    好政客：关于政治候选人动机和政府绩效的实验性证据
    Saad Gulzar, Muhammad Yasir Khan
12. 12.International Comovement in the Global Production Network
    全球生产网络中的国际联动性
    Zhen Huo, Andrei A Levchenko, Nitya Pandalai-Nayar
13. 13.Transhumant Pastoralism, Climate Change, and Conflict in Africa
    非洲的游牧牧业、气候变化与冲突
    Eoin F McGuirk, Nathan Nunn
14. 14.Reservation Raises: The Aggregate Labour Supply Curve at the Extensive Margin
    保留加薪：广泛边际上的总劳动供给曲线
    Preston Mui, Benjamin Schoefer
15. 15. Robust Implementation with Costly Information
    成本信息下的稳健实施机制
    Harry Pei, Bruno Strulovici
16. 16. The Causal Impact of Socio-Emotional Skills Training on Educational Success
    社会情感能力培训对教育成功的因果影响
    Giuseppe Sorrenti, Ulf Zölitz, Denis Ribeaud, Manuel Eisner
17. 17.Surviving Competition: Neighbourhood Shops versus Convenience Chains
    生存竞争：社区小店与便利店连锁
    Miguel Ángel Talamas Marcos
18. 18. Estimating Equilibrium in Health Insurance Exchanges: Price Competition and Subsidy Design under the ACA
    估计健康保险交易所的均衡：ACA下的价格竞争与补贴设计
    Pietro Tebaldi

文章摘要

Labour Market Screening and the Design of Social Insurance: An Equilibrium Analysis of the Labour Market for the Disabled
劳动力市场筛选与社会保险设计：对残疾人劳动力市场的均衡分析

Naoki Aizawa, Soojin Kim, Serena Rhee

This article studies how firms’ screening incentives in the labour market affect the optimal design of social insurance programs and quantitatively assesses the U.S. disability policies accounting for firms’ screening of the disabled. We develop an equilibrium search model where workers with different productivities have heterogeneous preferences over non-wage benefits and firms cannot offer an employment contract that explicitly depends on worker types. In this environment, firms may use contracts to screen out a certain type of workers, distorting employment rates and contracts in equilibrium. Therefore, the optimal structure of social insurance policies depends on firms’ screening incentives. We extend and structurally estimate this framework to quantitatively understand the inefficiencies arising from firms’ incentives to screen out disabled workers and examine the optimal joint design of disability insurance (DI) and various forms of firm subsidies. We find that hiring subsidies mitigate screening distortions; at the same time, they interact with DI by reducing the labour supply disincentives it generates. The optimal policy structure leads to a considerable welfare gain by simultaneously making firm subsidies and DI benefits more generous.

本文研究了劳动力市场中企业的筛选激励如何影响社会福利项目设计的最优性，并定量评估了考虑企业对残疾人筛选的美国残疾人政策。我们构建了一个均衡搜寻模型，在该模型中，不同生产力的工人对非工资福利的偏好存在异质性，企业不能提供明确依赖于工人类型的雇佣合同。在这种环境下，企业可能会利用合同筛选出某一类工人，从而扭曲均衡中的就业率和合同。因此，社会福利政策的最优结构取决于企业的筛选激励。我们扩展并结构化估计了这一框架，以定量理解企业筛选残疾人激励所产生的效率低下问题，并检验了残疾保险（DI）和各种形式的企业补贴的最优联合设计。我们发现，雇佣补贴可以减轻筛选扭曲；同时，它们与DI相互作用，减少了DI产生的劳动力供应抑制。最优政策结构通过同时增加企业补贴和DI福利，带来了相当可观的福利收益。

Optimal Allocation via Waitlists: Simplicity Through Information Design
通过候补名单进行最优分配：信息设计的简单实现

Itai Ashlagi, Faidra Monachou, Afshin Nikzad

We study non-monetary markets where objects that arrive over time are allocated to unit-demand agents with private types, such as in the allocation of public housing or deceased-donor organs. An agent’s value for an object is supermodular in her type and the object quality, and her payoff is her value minus her waiting cost. The social planner’s objective is a weighted sum of allocative efficiency (i.e. the sum of values) and welfare (i.e. the sum of payoffs). We identify optimal mechanisms in the class of direct-revelation mechanisms. When the social planner can design the information disclosed to the agents about the objects, the optimal mechanism has a simple implementation: a first-come first-served waitlist with deferrals. In this implementation, the object qualities are partitioned into intervals; only the interval containing the object quality is disclosed to agents. When the planner places a higher weight on welfare, optimal disclosure policies become coarser.

我们研究的是在非货币市场，随着时间推移而到达的物品被分配给具有私人类型的单位需求代理人，例如公共住房或已故捐赠者器官的分配。代理人对物品的价值是其类型和物品质量的超模态，其报酬是其价值减去等待成本。社会规划者的目标是分配效率（即价值总和）和福利（即报酬总和）的加权和。我们确定了直接显示机制中的最优机制。当社会规划者可以设计向代理人披露的对象信息时，最优机制的实施方法很简单：先到先得的候补，且有延迟。在这种机制中，对象的质量被划分为若干区间；只有包含对象质量的区间才会向代理人披露。当规划者对福利的权重较高时，最优的披露政策就会变得更粗略。

Inefficient Automation
低效的自动化

Martin Beraja, Nathan Zorzi

How should the government respond to automation? We study this question in a heterogeneous agent model that takes worker displacement seriously. We recognize that displaced workers face two frictions in practice: reallocation is slow and borrowing is limited. We analyze a second best problem where the government can tax automation but lacks redistributive tools to fully alleviate borrowing frictions. The equilibrium is (constrained) inefficient and automation is excessive. Firms do not internalize that automation depresses the income of automated workers early on during the transition, precisely when they become borrowing constrained. The government finds it optimal to slow down automation on efficiency grounds, even when it does not value equity. Quantitatively, the optimal speed of automation is considerably lower than at the laissez-faire. The optimal policy improves efficiency and delivers meaningful welfare gains.

政府应该如何应对自动化？我们在一个考虑工人被替代的异质性代理人模型中研究了这个问题。我们认识到，被替代的工人在实践中面临两个摩擦：重新分配缓慢且借贷有限。我们分析了一个次优问题，政府可以对自动化征税，但缺乏完全缓解借贷摩擦的再分配工具。均衡是（受限的）低效的，自动化过度。企业没有内化自动化在转型初期就压低了被自动化工人的收入，而这正是他们借贷受限的时候。政府发现从效率角度出发，减缓自动化是最优的，即使它并不重视公平。从定量上看，自动化的最优速度远低于自由放任下的速度。最优政策提高了效率并带来了有意义的福利收益。

Migration and the Value of Social Networks
移民与社会网络的价值

Joshua E Blumenstock, Guanghua Chi, Xu Tan

How do social networks influence the decision to migrate? Prior work suggests two distinct mechanisms that have historically been difficult to differentiate: as a conduit of information, and as a source of social and economic support. We disentangle these mechanisms using a massive “digital trace” dataset that allows us to observe the migration decisions made by millions of individuals over several years, as well as the complete social network of each person in the months before and after migration. These data allow us to establish a new set of stylized facts about the relationship between social networks and migration. Our main analysis indicates that the average migrant derives more social capital from “interconnected” networks that provide social support than from “extensive” networks that efficiently transmit information.

社会网络如何影响移民决策？以往的研究提出了两种历来难以区分的不同机制：作为信息的传递渠道，以及作为社会和经济支持的来源。我们利用一个庞大的“数字痕迹”数据集来区分这两种机制，该数据集使我们能够观察数百万个人在数年间的移民决策，以及每个人在移民前后几个月的完整社会网络。这些数据使我们能够建立关于社会网络与移民关系的一组新的典型事实。我们的主要分析表明，平均移民从提供社会支持的“互联”网络中获得的社会资本，比从高效传递信息的“广泛”网络中获得的更多。

Private Sector Provision as an “Escape Valve”: The Mexico Diabetes Experiment
私营部门提供作为“减压阀”：墨西哥糖尿病实验

Ari Bronsoler, Jonathan Gruber, Enrique Seira

Public health systems are dominant in much of the world but often face fiscal constraints that lead to rationing of care. As a result, private sector healthcare providers could in theory beneficially supplement public systems, but evaluating the benefits of private alternatives has been challenging. We evaluate a private supplement to the free public health system for one of the world’s deadliest health problems, diabetes. We estimate enormous impacts of the private supplement, increasing the share of those treated who are under control by 69%. This effect arises through both improved treatment compliance and health behavior. We find diabetes complications fall in the short run, and that the net costs of this intervention are one-third of the gross costs. The returns to private care do not appear to reflect more productive delivery but rather more attachment to medical care, offering lessons for improving the public system.

公共卫生系统在世界大部分地区占主导地位，但常常面临财政限制，导致医疗配给。因此，私营部门的医疗服务提供商理论上可以有益地补充公共系统，但评估私营替代方案的好处一直很有挑战性。我们评估了针对世界上最致命的健康问题之一——糖尿病的免费公共医疗系统的私营补充。我们估计私营补充产生了巨大的影响，使得到治疗且病情得到控制的人所占比例增加了69%。这种效果是通过改善治疗依从性和健康行为实现的。我们发现糖尿病并发症在短期内有所下降，而且这种干预的净成本仅为总成本的三分之一。私营护理的回报似乎并不反映更有生产力的交付，而是更多地依附于医疗护理，为改进公共系统提供了经验教训。

Adaptive Estimation and Uniform Confidence Bands for Nonparametric Structural Functions and Elasticities
非参数结构函数和弹性的自适应估计与均匀置信带

Xiaohong Chen, Timothy Christensen, Sid Kankanala

We introduce two data-driven procedures for optimal estimation and inference in nonparametric models using instrumental variables. The first is a data-driven choice of sieve dimension for a popular class of sieve two-stage least-squares estimators. When implemented with this choice, estimators of both the structural function and its derivatives (such as elasticities) converge at the fastest possible (i.e. minimax) rates in sup-norm. The second is for constructing uniform confidence bands (UCBs) for and its derivatives. Our UCBs guarantee coverage over a generic class of data-generating processes and contract at the minimax rate, possibly up to a logarithmic factor. As such, our UCBs are asymptotically more efficient than UCBs based on the usual approach of undersmoothing. As an application, we estimate the elasticity of the intensive margin of firm exports in a monopolistic competition model of international trade. Simulations illustrate the good performance of our procedures in empirically calibrated designs. Our results provide evidence against common parameterizations of the distribution of unobserved firm heterogeneity.

我们引入了两种使用工具变量在非参数模型中进行最优估计和推断的数据驱动程序。第一种是为一类流行的筛选两阶段最小二乘估计进行数据驱动的筛选维度选择。当采用这种选择时，结构函数及其导数（如弹性）的估计在上确界范数中以最快可能的（即极小极大）速率收敛。第二种是构建函数及其导数的均匀置信带（UCBs）。我们的UCBs在一般类数据生成过程中保证覆盖，并以极小极大速率收缩，可能最多相差一个对数因子。因此，我们的UCBs渐近地比基于通常的欠平滑方法的UCBs更有效。作为应用，我们在国际贸易的垄断竞争模型中估计了企业出口的边际弹性。模拟说明了我们的程序在经验校准设计中的良好表现。我们的结果为反对常见的未观察到的企业异质性分布参数化提供了证据。

Information Spillovers and Sovereign Debt: Theory Meets the Eurozone Crisis
信息溢出与主权债务：理论与欧元区危机

Harold L Cole, Daniel Neuhann, Guillermo Ordoñez

We develop a theory of information spillovers in sovereign bond markets in which investors can learn about default risk before trading in primary and secondary markets. If primary markets are structured as multi-unit discriminatory-price auctions, an endogenous winner’s curse leads to strategic complementarities in information acquisition. Shocks to default risk in one country may trigger crisis episodes with widespread information acquisition, sharp increases in the level and volatility of yields in risky countries, low and stable yields in safe countries, market segmentation, and arbitrage profits between primary and secondary markets. These predictions are consistent with the dynamics of auction informativeness during the Eurozone Sovereign Debt Crisis, which we measure using the reaction of secondary market yields to primary market yields.

我们发展了一个主权债券市场中信息溢出的理论，在该市场中，投资者可以在一级市场和二级市场交易之前了解违约风险。如果一级市场被设计为多单位歧视性价格拍卖，那么内生的赢家诅咒将导致信息获取的战略互补性。一个国家的违约风险冲击可能会引发危机事件，导致广泛的信息获取，风险国家收益率水平和波动性的急剧上升，安全国家收益率的低水平和稳定性，市场分割，以及一级市场和二级市场之间的套利利润。这些预测与欧元区主权债务危机期间拍卖信息动态一致，我们通过二级市场收益率对一级市场收益率的反应来衡量这种动态。

Partially Linear Models under Data Combination
数据组合下的偏线性模型

X D’Haultfœuille, C Gaillac, A Maurel

We study partially linear models when the outcome of interest and some of the covariates are observed in two different datasets that cannot be linked. This type of data combination problem arises very frequently in empirical microeconomics. Using recent tools from optimal transport theory, we derive a constructive characterization of the sharp identified set. We then build on this result and develop a novel inference method that exploits the specific geometric properties of the identified set. Our method exhibits good performances in finite samples, while remaining very tractable. We apply our approach to study intergenerational income mobility over the period 1850–1930 in the U.S. Our method allows us to relax the exclusion restrictions used in earlier work, while delivering confidence regions that are informative.

我们研究了当感兴趣的因变量和一些协变量在两个无法链接的不同数据集中被观察到时的偏线性模型。这种数据组合问题在实证微观经济学中非常常见。利用最优传输理论的最新工具，我们推导出了尖锐识别集的构造性特征。然后我们在此基础上，开发了一种新的推断方法，该方法利用了识别集的特定几何属性。我们的方法在有限样本中表现出良好的性能，同时保持高度可操作性。我们将我们的方法应用于研究美国1850-1930年期间的代际收入流动性。我们的方法允许我们放宽早期工作中使用的排除限制，同时提供信息量丰富的置信区间。

Too Domestic to Fail: Liquidity Provision and National Champions
太“国内”而不能倒闭：跨国企业的全球性与国家性

Emmanuel Farhi, Jean Tirole

Authorities’ support policies shape the location and continuation of industrial and banking activity on their soil. Firms’ locus of activity depends on their prospect of receiving financial assistance in distress and therefore on factors such as countries’ relative resilience. We predict that global firms are global in life and national in death; and that they become less global when competition is more intense, times are turbulent, and international risk sharing (say, through swap lines) weak. We analyse the competitive benefits of industrial and banking policies as well as their limitations, such as currency appreciation.

政府当局的支持政策塑造了在其领土上的工业和银行业活动的位置和延续。企业的活动位置取决于其在困境中获得财政援助的前景，因此也取决于国家的相对韧性等因素。我们预测，跨国企业在生时是全球性的，在死时是国家性的；并且当竞争更激烈、时代动荡以及国际风险分担（例如通过互换额度）较弱时，它们会变得不那么全球化。我们分析了工业和银行政策的竞争优势以及它们的局限性，如货币升值。

The Climate in Climate Economics
气候经济学中的气候

Doris Folini, Aleksandra Friedl, Felix Kübler, Simon Scheidegger

To analyse climate change mitigation strategies, economists rely on simplified climate models—so-called climate emulators—that provide a realistic quantitative link between CO2 emissions and global warming at low computational costs. In this paper, we propose a generic and transparent calibration and evaluation strategy for these climate emulators that are based on freely and easily accessible state-of-the-art benchmark data from climate sciences. We demonstrate that the appropriate choice of the free model parameters can be of key relevance for the predicted social cost of carbon. The key idea we put forward is to calibrate the simplified climate models to benchmark data from comprehensive global climate models that took part in the coupled model intercomparison project, phase 5 (CMIP5). In particular, we propose to use four different test cases that are considered pivotal in the climate science literature: two highly idealized tests to separately calibrate and evaluate the carbon cycle and temperature response, an idealized test to quantify the transient climate response, and a final test to evaluate the performance for scenarios close to those arising from economic models, and that include exogenous forcing. As a concrete example, we re-calibrate the climate part of the widely used DICE-2016, fathoming the CMIP5 uncertainty range of model responses: the multi-model mean as well as extreme, but still permissible climate sensitivities and carbon cycle responses. We demonstrate that the functional form of the climate emulator of the DICE-2016 model is fit for purpose, despite its simplicity, but its carbon cycle and temperature equations are miscalibrated, leading to the conclusion that one may want to be skeptical about predictions derived from DICE-2016. We examine the importance of the calibration for the social cost of carbon in the context of a partial equilibrium setting where interest rates are exogenous, as well as the simple general equilibrium setting from DICE-2016. We find that the model uncertainty from different consistent calibrations of the climate system can change the social cost of carbon by a factor of 4 if one assumes a quadratic damage function. When calibrated to the multi-model mean, our model predicts similar values for the social cost of carbon as the original DICE-2016, but with a strongly reduced sensitivity to the discount rate and about 1 degree less long-term warming. The social cost of carbon in DICE-2016 is oversensitive to the discount rate, leading to extreme comparative statics responses to changes in preferences.

为了分析气候变化减缓策略，经济学家依赖于简化的气候模型——所谓的气候模拟方法——这些模型以较低的计算成本提供了二氧化碳排放与全球变暖之间的真实定量联系。在本文中，我们提出了一个通用且透明的校准和评估策略，用于这些基于气候科学中免费且易于获取的最新基准数据的气候模拟方法。我们证明，适当选择自由模型参数对于预测碳的社会成本至关重要。我们提出的关键想法是将简化的气候模型校准到参与耦合模型比较项目第五阶段（CMIP5）的综合全球气候模型的基准数据。特别是，我们建议使用气候科学文献中认为关键的四种不同测试案例：两个高度理想化的测试，分别用于校准和评估碳循环和温度响应；一个理想化的测试，用于量化瞬态气候响应；以及一个最终测试，用于评估接近经济模型产生的场景的性能，这些场景包括外生强迫。以一个具体例子，我们重新校准了广泛使用的DICE-2016的气候部分，探索了CMIP5模型响应的不确定性范围：多模型平均值以及极端但仍然可接受的气候敏感性和碳循环响应。我们证明，尽管DICE-2016模型的气候模拟器的功能形式适合其目的，但其碳循环和温度方程校准错误，这导致人们可能对DICE-2016得出的预测持怀疑态度。我们在部分均衡设置（其中利率是外生的）以及DICE-2016的简单一般均衡设置中，检验了校准对于碳的社会成本的重要性。我们发现，如果假设一个二次损害函数，那么气候系统不同一致校准的模型不确定性可能会使碳的社会成本变化4倍。当校准到多模型平均值时，我们的模型预测的碳的社会成本与原始DICE-2016相似，但对贴现率的敏感性大幅降低，长期变暖减少了约1度。DICE-2016中碳的社会成本对贴现率过于敏感，导致对偏好变化的比较静态响应极端。

Good Politicians: Experimental Evidence on Motivations for Political Candidacy and Government Performance
好政客：关于政治候选人动机和政府绩效的实验性证据

Saad Gulzar, Muhammad Yasir Khan

How can we motivate good politicians—those that will carry out policy that is responsive to citizens’ preferences—to enter politics? In a field experiment in Pakistan, we vary how political office is portrayed to ordinary citizens. Emphasizing prosocial motives for holding political office instead of personal returns—such as the ability to help others versus enhancing one’s own respect and status—raises the likelihood that individuals run for office and that voters elect them. A year later, the treatment improves the alignment of policy with citizens’ preferences. These effects emerge only when treatments are randomly delivered in a public setting. Taken together, the results demonstrate that how politics is perceived shapes who decides to run for office, who is elected, as well the policies that democracies deliver.

我们如何激励好政客——那些会执行符合公民偏好的政策的人——进入政坛？在巴基斯坦的一项实地实验中，我们改变了向普通公民展示政治职位的方式。强调持有政治职位的亲社会动机而不是个人回报——例如帮助他人的能力与增强自身的尊重和地位相对——会增加个人竞选公职以及选民选举他们的可能性。一年后，这种处理方式改善了政策与公民偏好的一致性。这些效应仅在处理方式在公共场合随机传递时才会出现。综合来看，这些结果表明，政治的被感知方式塑造了谁决定竞选公职、谁被选举以及民主制度所交付的政策。

International Comovement in the Global Production Network
全球生产网络中的国际联动性

Zhen Huo, Andrei A Levchenko, Nitya Pandalai-Nayar

This article provides a general framework to study the role of production networks in international GDP comovement. We first derive an additive decomposition of bilateral GDP comovement into components capturing shock transmission and shock correlation. We quantify this decomposition in a parsimonious multi-country, multi-sector dynamic network propagation model, using data for the G7 countries over the period 1978–2007. Our main finding is that while the network transmission of shocks is quantitatively important, it accounts for a minority of observed comovement under the estimated range of structural elasticities. Contemporaneous responses to correlated shocks in the production network are more successful at generating comovement than intertemporal propagation through capital accumulation. Extensions with multiple shocks, nominal rigidities, and international financial integration leave our main result unchanged. A combination of TFP and labour supply shocks is quantitatively successful at reproducing the observed international business cycle.

本文提供了一个一般性框架，用于研究生产网络在国际GDP联动性中的作用。我们首先推导出双边GDP联动性的加法分解，将其分解为捕捉冲击传递和冲击相关的成分。我们使用1978-2007年G7国家的数据，在一个简洁的多国、多部门动态网络传播模型中量化了这种分解。我们的主要发现是，尽管冲击的网络传递在数量上很重要，但在估计的结构弹性范围内，它只占观察到的联动性的一小部分。生产网络中对相关冲击的同期响应比通过资本积累的时际传播更成功地产生联动性。引入多重冲击、名义刚性和国际金融一体化的扩展并未改变我们的主要结果。TFP和劳动力供应冲击的组合在数量上成功地复制了观察到的国际商业周期。

Transhumant Pastoralism, Climate Change, and Conflict in Africa
非洲的游牧牧业、气候变化与冲突

Eoin F McGuirk, Nathan Nunn

We consider the effects of climate change on seasonally migrant populations that herd livestock—i.e. transhumant pastoralists—in Africa. Traditionally, transhumant pastoralists benefit from a cooperative relationship with sedentary agriculturalists whereby arable land is used for crop farming in the wet season and animal grazing in the dry season. Rainfall scarcity can disrupt this arrangement by inducing pastoral groups to migrate to agricultural lands before the harvest, causing conflict to emerge. We examine this hypothesis by combining ethnographic information on the traditional locations of transhumant pastoralists and sedentary agriculturalists with high-resolution data on the location and timing of rainfall and violent conflict events in Africa from 1989 to 2018. We find that reduced rainfall in the territory of transhumant pastoralists leads to conflict in neighbouring areas. Consistent with the proposed mechanism, the conflicts are concentrated in agricultural areas; they occur during the wet season and not the dry season; and they are due to rainfall’s impact on plant biomass growth. Since pastoralists tend to be Muslim and agriculturalists Christian, this mechanism accounts for a sizable proportion of the rapid rise in religious conflict observed in recent decades. Regarding policy responses, we find that development aid projects tend not to mitigate the effects that we document. By contrast, the effects are reduced when transhumant pastoralists have greater power in national government, suggesting that more equal political representation is conducive to peace.

我们考虑了气候变化对非洲季节性迁徙的畜牧人群——即游牧牧民——的影响。传统上，游牧牧民与定居农民之间存在着一种合作关系，可耕地在雨季用于农作物种植，在旱季用于动物放牧。降雨稀少会破坏这种安排，促使牧群在收获前迁移到农田，从而引发冲突。我们通过将游牧牧民和定居农民的传统位置的民族志信息与1989年至2018年非洲降雨和暴力冲突事件的位置和时间的高分辨率数据相结合，来检验这一假设。我们发现，游牧牧民领地的降雨减少会导致邻近地区发生冲突。与所提出的机制一致，这些冲突集中在农业地区；它们发生在雨季而不是旱季；并且是由于降雨对植物生物量生长的影响。由于牧民倾向于信仰伊斯兰教，而农民信仰基督教，这一机制解释了近年来宗教冲突迅速上升的相当一部分。在政策回应方面，我们发现发展援助项目往往不能缓解我们记录的影响。相比之下，当游牧牧民在国家政府中拥有更大权力时，这些影响会减少，这表明更平等的政治代表有利于和平。

Reservation Raises: The Aggregate Labour Supply Curve at the Extensive Margin
保留加薪：广泛边际上的总劳动供给曲线

Preston Mui, Benjamin Schoefer

We measure desired labour supply at the extensive (employment) margin in two representative surveys of the U.S. and German populations. We elicit reservation raises: the percent wage change that renders a given individual indifferent between employment and nonemployment. It is equal to her reservation wage divided by her actual, or potential, wage. The reservation raise distribution is the nonparametric aggregate labour supply curve. Locally, the curve exhibits large short-run elasticities above 3, consistent with business cycle evidence. For larger upward shifts, arc elasticities shrink towards 0.5, consistent with quasi-experimental evidence from tax holidays. Existing models fail to match this nonconstant, asymmetric curve.

我们在对美国和德国人口进行的两项代表性调查中测量了广泛（就业）边际的期望劳动力供应。我们得出了保留加薪：使特定个人在就业与非就业之间无差异的工资变化百分比。它等于保留工资除以实际或潜在工资。保留加薪分布是非参数的总劳动力供给曲线。从局部来看，该曲线的短期弹性大于 3，与商业周期的证据相符。对于较大的上移，弧形弹性会缩小至 0.5，这与免税期的准实验证据一致。现有模型无法与这种非恒定、非对称的曲线相匹配。

Robust Implementation with Costly Information
成本信息下的稳健实施机制

Harry Pei, Bruno Strulovici

We construct mechanisms that can robustly implement any desired social choice function when (1) agents may incur a cost to learn the state of the world, (2) with small probability, agents’ preferences can be arbitrarily different from some baseline known to the mechanism designer, and (3) the mechanism designer does not know agents’ beliefs and higher-order beliefs about one another’s preferences. The mechanisms we propose have a natural interpretation and do not require the mechanism designer to be able to verify the state ex post. We also establish impossibility results for stronger notions of robust implementation.

我们构建了一种机制，能够在以下情况下稳健地实施任何期望的社会选择函数：（1）代理人可能需要承担学习世界状态的成本，（2）以很小的概率，代理人的偏好可能与机制设计者所知的某个基线大相径庭，（3）机制设计者不知道代理人彼此之间关于偏好的信念和高阶信念。我们提出的机制具有自然的解释，并且不需要机制设计者能够在事后验证状态。我们还为更强大的稳健实施概念建立了不可能性结果。

The Causal Impact of Socio-Emotional Skills Training on Educational Success
社会情感能力培训对教育成功的因果影响

Giuseppe Sorrenti, Ulf Zölitz, Denis Ribeaud, Manuel Eisner

We study the long-term effects of a randomized intervention targeting children's socio-emotional skills. The classroom-based intervention for primary school children has positive impacts that persist for over a decade. Treated children become more likely to complete academic high school and enrol in university. Two mechanisms drive these results. Treated children show fewer attention deficit/hyperactivity disorder symptoms: they are less impulsive and less disruptive. They also attain higher grades, but they do not score higher on standardized tests. The long-term effects on educational attainment thus appear to be driven by changes in socio-emotional skills rather than cognitive skills.

我们研究了一项针对儿童社会情感能力的随机干预的长期影响。这项面向小学生的课堂干预措施产生了持续超过十年的积极影响。接受处理的儿童完成学术高中和进入大学的可能性更大。两种机制推动了这些结果。接受处理的儿童表现出更少的注意力缺陷/多动障碍症状：他们更少冲动和更少扰乱。他们的成绩也更高，但在标准化测试中得分并不更高。因此，对教育成就的长期影响似乎是由社会情感能力的变化而非认知能力的变化所驱动的。

Surviving Competition: Neighbourhood Shops versus Convenience Chains
生存竞争：社区小店与便利店连锁

Miguel Ángel Talamas Marcos

Hundreds of millions of microenterprises in emerging economies face increased competition from the entry and expansion of large firms that offer similar products. This paper examines the impacts of the opening of chain-run convenience stores on one of the world’s most ubiquitous microenterprises: owner-operated shops. To address endogeneity in time and location of chains’ opening, I pair two-way fixed effects with a novel instrument that shifts the profitability of chains but not of shops at the neighbourhood level. Expanding the number of chain outlets from zero to the neighbourhood average of 6.7 stores reduces the number of shops by 15%, a decline driven not by increased shop exits but by decreased shop entries. Shops retain their sales of fresh products and keep 96% of their customers, but customers visit shops less frequently and spend less on packaged goods. Surviving shops leverage competitive advantages stemming from being owner operated, such as lower agency costs, cultivating relationships with neighbours, and offering customers informal credit. The welfare gains of convenience chains replacing shops increase with household income; the poorest households experience a welfare loss.

新兴经济体中数以亿计的微型企业面临着大型企业进入和扩张带来的日益激烈的竞争，这些大型企业提供的产品类似。本文考察了连锁便利店的开设对世界上最普遍的微型企业之一：业主经营商店的影响。为了解决连锁店开业时间和地点的内生性问题，我将双向固定效应与一种新的工具变量相结合，该工具变量改变了社区层面连锁店的盈利能力，但不影响商店的盈利能力。将连锁店数量从零增加到社区平均水平的6.7家商店，使商店数量减少了15%，这种下降并非由商店退出增加所致，而是由商店进入减少所致。商店保持了其新鲜产品的销售额，并保留了96%的顾客，但顾客光顾商店的频率降低，且在包装商品上的支出减少。幸存的商店利用了业主经营所带来的竞争优势，例如较低的代理成本、与邻居培养关系以及向顾客提供非正式信贷。便利店取代商店的福利收益随着家庭收入的增加而增加；最贫困的家庭经历了福利损失。

Estimating Equilibrium in Health Insurance Exchanges: Price Competition and Subsidy Design under the ACA
估计健康保险交易所的均衡：ACA下的价格竞争与补贴设计

Pietro Tebaldi

Regulations to design private yet publicly sponsored health insurance markets are increasingly adopted in many OECD countries. Here I combine data and economic theory to analyse the interaction between insurers’ competition and the design of premium subsidies in determining equilibrium outcomes. My empirical model includes adverse selection, rich heterogeneity in preferences for vertically and horizontally differentiated plans and accommodates alternative assumptions on pricing conduct. In the context of the Affordable Care Act in the U.S., I estimate the joint distribution of preferences and expected cost using Californian administrative records on 3.4 million plan choices between 2014 and 2017, combined with plan and survey data on medical claims. An empirical horse race between conduct assumptions favours oligopoly pricing over perfect competition. Considering alternative subsidy designs shows that, in equilibrium, shifting subsidy generosity toward the “young invincibles” would lower premiums for all enrolees while increasing enrolment and profits.

设计私人但由公共资助的健康保险市场的法规在许多经合组织国家越来越被采用。在这里，我结合数据和经济理论来分析保险公司的竞争与保费补贴设计在决定均衡结果中的相互作用。我的实证模型包括逆向选择、对垂直和水平差异化计划偏好的丰富异质性，并容纳了关于定价行为的不同假设。在美国《平价医疗法案》的背景下，我使用2014年至2017年之间的340万份计划选择的加利福尼亚行政记录，结合计划和医疗索赔的调查数据，估计偏好和预期成本的联合分布。在不同行为假设之间的实证竞赛中，寡头垄断定价优于完全竞争。考虑替代补贴设计表明，在均衡状态下，将补贴慷慨度向“年轻无敌者”倾斜，将降低所有参保者的保费，同时增加参保数量和利润。