编者按：美国全国经济研究所（NBER）是美国最大的经济学研究组织，其发布的工作论文代表着经济学研究最新的成果，每周一发布新论文。本周（8.19-8.25）共发布 30 篇新工作论文，本期将会推送中间 10 篇论文的题目与摘要，供读者学习。
学术财经研究团队翻译。
Spooky Boundaries at a Distance: Inductive Bias, Dynamic Models, and Behavioral Macro
远距的神秘边界：归纳偏差、动态模型与行为宏观经济学
Mahdi E. Kahou, Jesús Fernández-Villaverde, Sebastian Gomez-Cardona, Jesse Perla, and Jan Rosa #32850
Abstract: In the long run, we are all dead. Nonetheless, when studying the short-run dynamics of economic models, it is crucial to consider boundary conditions that govern long-run, forward-looking behavior, such as transversality conditions. We demonstrate that machine learning (ML) can automatically satisfy these conditions due to its inherent inductive bias toward finding flat solutions to functional equations. This characteristic enables ML algorithms to solve for transition dynamics, ensuring that long-run boundary conditions are approximately met. ML can even select the correct equilibria in cases of steady-state multiplicity. Additionally, the inductive bias provides a foundation for modeling forward-looking behavioral agents with self-consistent expectations.
摘要：从长远来看，我们都将面临死亡。然而，在研究经济模型的短期动态时，考虑控制长期前瞻性行为的边界条件，如横向条件，是至关重要的。我们展示了机器学习（ML）可以自动满足这些条件，因为它具有固有的归纳偏差，倾向于找到函数方程的平坦解。这一特性使得ML算法能够解决过渡动态，确保长期边界条件得到大致满足。机器学习甚至可以在稳态多重性情况下选择正确的均衡。此外，归纳偏差为建模具有自洽预期的前瞻性行为主体提供了基础。
The Consumer Welfare Effects of Online Ads: Evidence from a 9-Year Experiment
在线广告对消费者福利的影响：来自9年实验的证据
Erik Brynjolfsson, Avinash Collis, Asad Liaqat, Daley Kutzman, Haritz Garro, Daniel Deisenroth, and Nils Wernerfelt #32846
Abstract: Research on the causal effects of online advertising on consumer welfare is limited due to challenges in running large-scale field experiments and tracking effects over extended periods. We analyze a long-running field experiment of online advertising in which a random 0.5% subset of all users are assigned to a group that does not ever see ever ads. We recruit a representative sample of Facebook users in the ads and no-ads groups and estimate their welfare gains from using Facebook using a series of incentive-compatible choice experiments. We find no significant differences in welfare gains from Facebook. Our estimates are relatively precisely estimated reflecting our large sample size (53,166 participants). Specifically, the minimum detectable difference in median valuations at standard thresholds is $3.18/month compared to a baseline valuation of $31.95/month for giving up access to Facebook. That is, we can reject the hypothesis that the median disutility from advertising exceeds 10% of the median baseline valuation. Our findings suggest that either the disutility of ads for consumers is relatively small, or that there are offsetting benefits, such as helping consumers find products and services of interest.
摘要：由于在进行大规模实地实验和跟踪长期效果时面临的挑战，关于在线广告对消费者福利的因果影响的研究较为有限。我们分析了一个长期的在线广告实地实验，其中随机选取了0.5%的用户群体，这些用户从未看到广告。我们招募了广告组和非广告组的Facebook用户代表样本，并通过一系列与激励相容的选择实验来估计他们使用Facebook的福利增益。我们发现Facebook的福利增益没有显著差异。我们的估计相对准确，反映了我们的样本量较大（53,166名参与者）。具体而言，标准阈值下的最小可检测差异为每月3.18美元，相较于每月31.95美元的基线估值，这是为了放弃访问Facebook。也就是说，我们可以拒绝广告带来的中位不利效用超过中位基线估值10%的假设。我们的发现表明，要么广告对消费者的不利效用相对较小，要么存在抵消的好处，例如帮助消费者找到感兴趣的产品和服务。
Political Partisanship and Remote Work: Evidence from U.S. States
政治派系与远程工作：来自美国各州的证据
Benjamin W. Cowan and Kairon Shayne D. Garcia #32834
Abstract: We examine how politics and policy have affected remote-work rates in the wake of the COVID-19 pandemic. Using the Current Population Survey, American Community Survey, and the American Time Use Survey, which have several different measures of remote work, we examine how trends in remote work vary by state-level characteristics. We show that state-level measures of the length and stringency of COVID protection policies are not correlated with changes in remote work from before to after the pandemic once a measure of political partisanship (Democratic vote share in the 2020 presidential election) is included in the model. An increase in 2020 Democratic vote share of one standard deviation (about 9 percentage points) is related to an increase in the likelihood of remote work by 1-2 percentage points and the share of remote work by about 3-5 percent. These effects represent roughly 15-25% of pre-COVID means. These results are robust to the inclusion of not only a rich set of individual controls (e.g., occupational telework potential) but also several different state-level controls, including COVID policy indices, cases and deaths, vaccination rates, and economic performance indicators. We conclude that relative increases in remote work across states that are associated with a higher 2020 Democratic vote share cannot be easily explained by differences in COVID-era policies or outcomes or differences in the nature of jobs across states.
摘要：我们研究了政治和政策在COVID-19疫情后如何影响远程工作率。通过使用《当前人口调查》、《美国社区调查》和《美国时间使用调查》，我们检查了不同州的远程工作趋势如何随州级特征的变化而变化。我们显示，一旦在模型中包含政治派系的度量（2020年总统选举中的民主党票数份额），州级COVID保护政策的长度和严格性与疫情前后远程工作的变化之间并不相关。2020年民主党票数份额增加一个标准差（约9个百分点）与远程工作可能性增加1-2个百分点以及远程工作份额增加约3-5%相关。这些影响大约占疫情前均值的15-25%。这些结果在包含丰富的个人控制变量（例如职业远程工作潜力）以及多个不同的州级控制变量（包括COVID政策指数、病例和死亡人数、疫苗接种率和经济表现指标）时依然稳健。我们得出结论，相对于2020年民主党票数份额较高的州，远程工作的相对增加不能简单地通过COVID时代政策或结果的差异，或州间职位性质的差异来解释。
Why Do Europeans Save? Micro-Evidence from the Household Finance and Consumption Survey
为什么欧洲人储蓄？来自家庭金融与消费调查的微观证据
Charles Yuji Horioka and Luigi Ventura #32838
Abstract: We analyze the saving motives of European households using micro-data from the Household Finance and Consumption Survey (HFCS), which is conducted by the European Central Bank. We find that the rank ordering of saving motives differs greatly depending on what criterion is used to rank them. For example, we find that the precautionary motive is the most important saving motive of European households when the proportion of households saving for each motive is used as the criterion to rank them but that the retirement motive is the most important saving motive of European households if the quantitative importance of each motive is taken into account. Moreover, the generosity of social safety nets seems to affect the importance of each saving motive, with saving for the retirement motive being less important in countries with generous public pension benefits and saving for the precautionary motive being less important in countries with generous health systems. These findings suggest that the retirement motive and the precautionary motive are the dominant motives for saving in Europe partly because social safety nets are not fully adequate. Finally, our findings suggest that the selfish life-cycle model is more applicable in Europe than is the altruism model.
摘要：我们使用欧洲中央银行进行的《家庭金融与消费调查》（HFCS）中的微观数据分析了欧洲家庭的储蓄动机。我们发现，储蓄动机的排序在不同的排序标准下差异很大。例如，当按照家庭为每种动机储蓄的比例来排序时，预防性动机是欧洲家庭最重要的储蓄动机；但如果考虑每种动机的定量重要性，则退休动机是最重要的储蓄动机。此外，社会保障网的慷慨程度似乎影响了每种储蓄动机的重要性，在公共养老金福利慷慨的国家，储蓄用于退休动机的重要性较低；而在医疗系统慷慨的国家，储蓄用于预防性动机的重要性较低。这些发现表明，退休动机和预防性动机在欧洲是主要的储蓄动机，部分原因是社会保障网不完全充分。最后，我们的研究结果表明，自私的生命周期模型在欧洲的适用性高于利他主义模型。
Managing Margins: PE Effects on Financial, Physical, and Human Capital
理利润率：私人股本对金融、实物和人力资本的影响
Michael R. Richards, Maggie Shi, and Christopher M. Whaley #32840
Abstract: Private equity (PE) plays an increasingly important role in the modern US economy. However, its impacts on owned-firms are incompletely understood. We exploit a historically large leveraged buyout of a national hospital chain to examine how the full life cycle of PE influences hospital-level revenues, technology sourcing, labor use, and financial performance. We find permanent improvements in hospital volumes and revenues. PE also reduces growth in full-time employees, with a suggestive partial substitution toward part-time workers. Technology adoption is restrained, but the number of vendors expands. Overall, PE has nuanced effects on hospital management, which translate to improved operating margins.
摘要：私人股本（PE）在现代美国经济中扮演着越来越重要的角色。然而，对其对所持有企业的影响的理解仍不完全。我们利用对一家国家级医院连锁的历史性大规模杠杆收购，研究私人股本的整个生命周期如何影响医院层面的收入、技术采购、劳动使用和财务表现。我们发现医院的业务量和收入都有了永久性的改善。私人股本还减少了全职员工的增长，部分转向兼职员工。技术采纳受到限制，但供应商的数量有所增加。总体而言，私人股本对医院管理的影响具有微妙的特点，这转化为运营利润率的改善。
Who Benefits from Retirement Saving Incentives in the U.S.? Evidence on Gaps in Retirement Wealth Accumulation by Race and Parental Income
谁从美国的退休储蓄激励中受益？有关种族和父母收入差距在退休财富积累中的证据
Taha Choukhmane, Jorge Colmenares, Cormac O'Dea, Jonathan L. Rothbaum, and Lawrence D.W. Schmidt #32843
Abstract: U.S. employers and the federal government devote over 1.5% of GDP annually toward promoting defined contribution (DC) retirement saving. Using a new employer-employee linked dataset covering millions of Americans, we show that this system of saving incentives benefits White workers and those with richer parents more than their similar-income coworkers who are Black or Hispanic or from lower-income families. Breaking the link between contribution choices and saving subsidies—through revenue-neutral reforms—could close the gaps in DC wealth between White and Black or Hispanic workers and between those with the richest and those with the poorest parents by approximately one-third.
摘要：美国雇主和联邦政府每年将超过GDP的1.5%用于促进确定贡献（DC）退休储蓄。通过使用涵盖数百万美国人的新的雇主-员工关联数据集，我们发现这一储蓄激励系统对白人员工和那些拥有更富裕父母的员工的好处大于他们的收入相似的黑人或西班牙裔员工以及来自低收入家庭的员工。通过收入中性改革打破贡献选择与储蓄补贴之间的联系，可以将白人和黑人或西班牙裔员工之间、以及拥有最富裕父母和最贫困父母之间的DC财富差距缩小约三分之一。
Credit When You Need It
在需要时获得信贷
Benjamin L. Collier, Daniel A. Hartley, Benjamin J. Keys, and Jing Xian Ng #32845
Abstract: We estimate the causal effect of emergency credit on households' finances after a negative shock. To do so, we link application data from the U.S. Federal Disaster Loan program, which provides loans to households that have uninsured damages from a federally-declared natural disaster, to a panel of credit records before and after the shock. We exploit a discontinuity in the loan approval rules that led applicants with debt-to-income ratios below 40% to be differentially likely to be approved. Using an instrumented difference-in-differences research design, we find that credit provision at the time of a shock significantly reduces severe financial distress, decreasing the likelihood of filing for bankruptcy by 61% in the three years following the disaster. We explore mechanisms using additional quasi-experimental variation in interest rates, finding support for a liquidity-based explanation. Credit provision in a time of crisis has real consumption effects in the form of additional car purchases even 3 years after loan receipt. Our findings suggest that well-timed liquidity provided to households in acute need can have substantial and persistent positive effects.
摘要：我们估计了紧急信贷在负面冲击后对家庭财务的因果影响。为此，我们将美国联邦灾难贷款计划的申请数据（该计划向遭受联邦宣布自然灾害的家庭提供贷款）与冲击前后的信用记录面板数据联系起来。我们利用贷款审批规则中的一个不连续性，导致债务与收入比低于40%的申请人更有可能获得批准。通过使用工具变量的差分-差分研究设计，我们发现，在冲击发生时提供的信贷显著减少了严重的财务困境，降低了灾后三年内申请破产的可能性61%。我们通过附加的准实验利率变化探索了机制，发现支持基于流动性的解释。即使在贷款发放后三年，危机时期的信贷提供仍对消费产生实际影响，例如增加汽车购买。我们的发现表明，及时向急需家庭提供流动性可以产生实质性和持久的积极效果。
A Business Case for Human Rights at Work? Experimental Evidence on Labor Trafficking and Child Labor at Brick Kilns in Bangladesh
工作场所人权的商业案例？来自孟加拉国砖窑的劳动人口贩运和童工的实验证据
Grant Miller, Debashish Biswas, Aprajit Mahajan, Kimberly Singer Babiarz, Nina R. Brooks, Jessie Brunner, Sania Ashraf, Jack Shane, Sameer Maithel, Shoeb Ahmed, Moogdho Mahzab, Mohammad Rofi Uddin, Mahbubur Rahman, and Stephen P. Luby #32829
Abstract: Globally, coercive labor (i.e., forced, bonded, and/or trafficked labor) and child labor are disproportionately prevalent in environments with weak regulatory enforcement and state capacity. Effective strategies for addressing them may therefore need to align with the private incentives of business owners, not relying on government action alone. Recognizing this, we test a ‘business case’ for improving work conditions and promoting human rights using a randomized controlled trial across nearly 300 brick kilns in Bangladesh. Among study kilns, rates of coercive and child labor are high: about 50% of sampled workers are trafficked, and about 70% of kilns use child labor. Our experiment introduced a production method that increased kiln productivity and revenue, and we test if these productivity gains in turn increase worker “compensation” (including better work conditions). Because adoption of the method requires important changes in worker routines, we also test if providing information to kiln owners about positively incentivizing workers to enhance adoption (and hence business revenue) can lead to better work conditions. We find no evidence that productivity gains alone reduced labor trafficking or child labor, but adding the information intervention reduced child labor by 25-30% without reducing revenue or increasing costs.
摘要：在全球范围内，强迫劳动（即强制劳动、债务奴役和/或人口贩运劳动）和童工在监管执行和国家能力薄弱的环境中尤为普遍。因此，解决这些问题的有效策略可能需要与企业主的私人激励相一致，而不仅仅依赖政府行动。认识到这一点，我们通过在孟加拉国近300个砖窑进行随机对照试验，测试了改善工作条件和促进人权的“商业案例”。在研究的砖窑中，强迫劳动和童工的比例很高：约50%的样本工人被贩运，约70%的砖窑使用童工。我们的实验引入了一种提高砖窑生产力和收入的生产方法，并测试这些生产力提升是否反过来增加了工人的“补偿”（包括改善的工作条件）。由于采用这种方法需要工人日常工作的重要变化，我们还测试了向砖窑老板提供有关积极激励工人的信息（从而提升业务收入）是否可以改善工作条件。我们没有发现仅仅提高生产力就能减少劳动贩运或童工，但加入信息干预后，童工减少了25-30%，且没有减少收入或增加成本。
Reducing Emissions and Air Pollution from the Informal Sector: Evidence from Bangladesh
减少来自非正规部门的排放和空气污染：来自孟加拉国的证据
Nina R. Brooks, Debashish Biswas, Sameer Maithel, Grant Miller, Aprajit Mahajan, M. Rofi Uddin, Shoeb Ahmed, Moogdho Mahzab, Mahbubur Rahman, and Stephen P. Luby #32794
Abstract: We present results from a randomized controlled trial in Bangladesh that introduced operational practices to improve energy efficiency and reduce emissions in 276 “zigzag” brick kilns. 65% of intervention kilns adopted the improved practices. Treatment assignment reduced energy use by 10.3% (p-value<0.001) and decreased CO2 and PM2.5 emissions by 171 metric tons and 0.45 metric tons, respectively, per kiln per year. Valuing the CO2 reductions using a social cost of carbon of $185/MT, we find that the social benefits outweigh costs by a factor of 190 to 1. The intervention, which required no new capital investment, also decreased fuel costs and increased brick quality. Our results demonstrate the potential for privately profitable, as well as publicly beneficial, improvements to address environmental problems in informal industries.
摘要：我们展示了在孟加拉国进行的一项随机对照试验的结果，该试验引入了改进能源效率和减少排放的操作实践，覆盖了276个“之”字形砖窑。65%的干预砖窑采纳了这些改进的实践。处理组的能源使用减少了10.3%（p值<0.001），二氧化碳和PM2.5的排放量分别减少了171公吨和0.45公吨。以每公吨185美元的碳社会成本来评估二氧化碳的减少，我们发现社会收益超过成本的比例为190:1。该干预措施无需新的资本投资，还减少了燃料成本并提高了砖块质量。我们的结果展示了在非正规行业中，既能带来私人盈利又对公众有益的环境改善的潜力。
Disemployment Effects of Unemployment Insurance: A Meta-Analysis
失业保险的失业效应：一项元分析
Jonathan P. Cohen and Peter Ganong #32832
Abstract: We systematically review studies of how unemployment benefits affect unemployment duration. Statistically significant findings are eleven times more likely to be published. Correcting for publication bias halves the average elasticity. Meta-analysis provides a principled way for sufficient statistics methods to aggregate estimates across policy contexts and speak to the optimality of large reforms. Although existing consumption drop-based approaches typically imply an optimal replacement rate near zero, our corrected estimates imply an optimal replacement rate of 28%. The "micro" elasticity is equal to the "macro" elasticity, suggesting that general equilibrium effects are unimportant or cancel out.
摘要：我们系统地回顾了关于失业救济如何影响失业持续时间的研究。统计显著的发现比其他结果更有可能被发表。纠正出版偏差后，平均弹性降低了一半。元分析为充分统计量方法提供了一种原则性的方式，用于在不同政策背景下汇总估计，并讨论大型改革的最优性。尽管现有基于消费下降的方法通常暗示最优替代率接近零，但我们修正后的估计结果表明，最优替代率为28%。“微观”弹性等于“宏观”弹性，这表明一般均衡效应不重要或相互抵消。
往期精选：
