在线平台的服务质量：关于Uber驾驶质量的实证证据

Susan Athey, Juan Camilo Castillo, and Bharat Chandar #33087

Abstract: Online marketplaces have adopted new quality control mechanisms that can accommodate a flexible pool of providers. In the context of ride-hailing, we measure the effectiveness of these mechanisms, which include ratings, incentives, and behavioral nudges. Using telemetry data as an objective measure of quality, we find that drivers not only respond to user preferences but also improve their behavior after receiving warnings about their low ratings. Furthermore, we use data from a randomized experiment to show that informing drivers about their past behavior improves quality, especially for low-performing drivers. Lastly, we find that UberX drivers exhibit behavior comparable to that of UberTaxi drivers, suggesting that Uber’s new quality control mechanisms successfully maintain a high level of service quality.

摘要：在线市场采用了新的质量控制机制，以适应灵活的服务提供者群体。在网约车的背景下，我们衡量了这些机制的有效性，包括评分、激励和行为引导。使用遥测数据作为质量的客观衡量标准，我们发现司机不仅会响应用户偏好，还会在收到低评分警告后改进其行为。此外，我们利用一项随机实验的数据表明，告知司机其过往行为可以提高服务质量，尤其是对于表现较差的司机。最后，我们发现UberX司机的行为与UberTaxi司机相当，这表明Uber的新质量控制机制成功保持了高水平的服务质量。

同志与信念：同伴影响对西点军校学员内战忠诚度的作用

Yuchen Guo, Matthew O. Jackson, and Ruixue Jia #33093

Abstract: We examine how peers influence the allegiances of West Point cadets in the American Civil War. Specifically, we analyze how quasi-random variations in the proportion of cadets from northern (low-slave) states influenced the decisions of cadets in choosing which army to join. A higher proportion of classmates from low-slave states significantly increased the likelihood that cadets from high-slave states joined the Union Army, while almost all cadets from low-slave states joined the Union Army (if they decided to join the war). Additionally, the higher the fraction of the population that were slaves in a cadet’s home state the lower the likelihood that the cadet joined the Union and the lower the peer influence. We also examine how cadets’ decisions affected their military rank and career outcomes. Our results highlight the importance of peer influence in major life decisions, particularly at critical historical junctures.

摘要：我们研究了同伴如何影响西点军校学员在美国内战中的忠诚选择。具体而言，我们分析了来自北方（低奴隶制）州的学员比例的准随机变化如何影响学员选择加入哪支军队的决定。较高比例的来自低奴隶制州的同学显著增加了来自高奴隶制州的学员加入联邦军队的可能性，而几乎所有来自低奴隶制州的学员（如果他们决定参战）都加入了联邦军。此外，学员家乡州的奴隶人口比例越高，学员加入联邦军的可能性就越低，同伴影响的作用也越弱。我们还考察了学员的决定如何影响他们的军衔和职业发展结果。我们的研究结果突显了同伴影响在重大人生决策中的重要性，尤其是在关键历史关头。

医生的执业偏好与医疗支出：来自商业支付方的证据

Jeffrey Clemens, Pierre-Thomas Léger, Yashna Nandan, and Robert Town #33090

Abstract: We examine the relationship between physician preferences and both the intensity and cost of care delivered to commercially insured heart attack patients. We match survey data on physician preferences, collected by Cutler, Skinner, Stern, and Wennberg (2019) (CSSW), to medical claims data from the Health Care Cost Institute, which spans over 50 million insurance beneficiaries. In contrast to CSSW, who find strong correlations between aggressive practice preferences and both expenditure and utilization for the Medicare population, we find relationships that are both economically and statistically smaller in magnitude within the commercially insured population. Variations in commercial insurers’ prices appear to play an important mediating role.

摘要：我们研究了医生偏好与向商业保险覆盖的心脏病患者提供的医疗强度和成本之间的关系。我们将Cutler、Skinner、Stern和Wennberg（2019）（CSSW）收集的关于医生偏好的调查数据与涵盖超过5000万保险受益人的医疗成本研究所的医疗索赔数据相匹配。与CSSW在其研究中发现的医生激进执业偏好与Medicare人群的支出和利用率之间的强相关性相比，我们在商业保险人群中发现的关系在经济和统计上的幅度都较小。商业保险公司价格的差异似乎在其中起到了重要的中介作用。

管制价格削减的长期影响：来自医疗保险的证据

Yunan Ji and Parker Rogers #33083

Abstract: We investigate the effects of substantial Medicare price reductions in the medical device industry, which amounted to a 61% decrease over 10 years for certain device types. Analyzing over 20 years of administrative and proprietary data, we find these price cuts led to a 25% decline in new product introductions and a 75% decrease in patent filings, indicating significant reductions in innovation activity. Manufacturers decreased market entry and increased outsourcing to foreign producers, associated with higher rates of product defects. Our calculations suggest the value of lost innovation may fully offset the direct cost savings from the price cuts. We propose that better-targeted pricing reforms could mitigate these negative effects. These findings underscore the need to balance cost containment with incentives for innovation and quality in policy design.

摘要：我们研究了医疗设备行业中医疗保险（Medicare）价格大幅削减的影响，在十年间某些设备类型的价格下降了61%。通过分析超过20年的行政和专有数据，我们发现这些价格削减导致新产品推出减少了25%，专利申请减少了75%，显示创新活动显著下降。制造商减少了市场进入，并增加了对外国生产商的外包，这与产品缺陷率的上升相关。我们的计算表明，失去的创新价值可能完全抵消了价格削减带来的直接成本节约。我们建议更有针对性的价格改革，以减轻这些负面影响。研究结果强调了在政策设计中平衡成本控制与激励创新和质量的必要性。

对住房密度的反感

Joseph Gyourko and Sean E. McCulloch #33078

Abstract: We characterize the distribution of suburban homeowners’ preferences for housing unit density. To measure welfare changes under counterfactual increases in density, we first construct a novel house-level measure of exposure to density and identify its price effects in a boundary discontinuity design. On the borders of municipalities with larger minimum lot sizes, lots are 3,000 ft² larger and houses are $40,000 costlier. We exploit the systematic variation in density exposure induced by these discontinuities to estimate price effects. We then connect these estimates to a structural hedonic model of housing choice to retrieve individuals’ preferences for density. Overall, we find an average welfare loss among incumbent homeowners from a 1/2 unit per acre increase in density (which is equivalent to a 0.3 standard deviation in density) of about $9,500, with significantly larger losses under counterfactual increases solely from rental units. There is other noteworthy heterogeneity in these preferences, too. Most households have only a moderate preference over density. The median welfare loss is only 55% of the average, implying a long, left tail of those with more extreme aversions to density. This tail disproportionately contains households in affluent, low density neighborhoods. In sum, our results document an important foundation of the demand for density regulation across U.S. suburbs that we hope serves as a valuable input into future research into the considerable costs of that policy.

摘要：我们描述了郊区房主对住房单位密度的偏好分布。为衡量假设性密度增加下的福利变化，我们首先构建了一种新的房屋级别的密度暴露指标，并通过边界不连续设计识别其价格影响。在最低地块面积要求更大的市镇边界上，地块面积平均增加了3,000平方英尺，房价则增加了40,000美元。我们利用这些不连续性所引发的密度暴露系统性变化来估计价格影响。接着，将这些估计值与住房选择的结构性享乐模型相联系，从而获得个人对密度的偏好。总体而言，我们发现当前业主在每英亩增加1/2个单位（相当于密度的0.3个标准差）情况下，平均福利损失约为9,500美元，并且在假设性增加仅来自租赁单位的情况下损失显著更大。此外，这些偏好中存在其他显著的异质性。大多数家庭对密度的偏好仅为中等程度，中位数的福利损失仅为平均水平的55%，这表明存在一条较长的左尾，包含对密度有极端厌恶的家庭。该左尾主要集中在富裕的低密度社区。综上所述，我们的研究结果记录了美国郊区对密度监管需求的重要基础，希望这一发现能为未来关于该政策的显著成本的研究提供有价值的参考。

人工智能与金融

Andrea L. Eisfeldt and Gregor Schubert #33076

Abstract: We provide evidence that the development and adoption of Generative AI is driving a significant technological shift for firms and for financial research. We review the literature on the impact of ChatGPT on firm value and provide directions for future research investigating the impact of this major technology shock. Finally, we review and describe innovations in research methods linked to improvements in AI tools, along with their applications. We offer a practical introduction to available tools and advice for researchers interested in using these tools.

摘要：我们提供了证据表明，生成式人工智能的发展和应用正推动企业和金融研究的重大技术变革。我们回顾了有关ChatGPT对公司价值影响的文献，并为未来研究这一重大技术冲击的影响指明了方向。最后，我们回顾并描述了与人工智能工具改进相关的研究方法创新及其应用。我们还为有兴趣使用这些工具的研究人员提供了关于现有工具的实用介绍和建议。

社区大学学生是否越来越多地选择高薪专业？来自马萨诸塞州的证据

Richard J. Murnane, John B. Willett, Aubrey McDonough, John P. Papay, and Ann J. Mantil #33073

Abstract: The labor-market payoff to workers with associate degrees in healthcare and STEM occupations is very high in Massachusetts. We examine whether this induced a growing proportion of students in MA community colleges (MACCs) to earn an associate degree (AD) in one of these fields. We do this by using multinomial logit analysis to compare trends across 12 cohorts of MACC entrants in the proportion of students who earned an AD in a healthcare or STEM program within six years of entry. We find a substantial increase across cohorts in the proportion of students who earned an AD in a STEM program, but not in the proportion who earned an AD in a healthcare program. We found differences in degree attainment by student gender, race/ethnicity, family income, and 10th-grade mathematics score. Interviews with MACC program leaders revealed that supply constraints hinder expansion of many healthcare AD programs, but not STEM programs.

摘要：在马萨诸塞州，拥有副学士学位的工人在医疗保健和STEM（科学、技术、工程、数学）职业中的劳动市场回报非常高。我们研究了这是否促使越来越多的马萨诸塞州社区大学（MACCs）学生在这些领域中获得副学士学位。为此，我们使用多项逻辑回归分析，比较了12个MACC入学群体在入学六年内获得医疗保健或STEM专业副学士学位的学生比例的趋势。我们发现，各个群体中获得STEM专业副学士学位的学生比例显著增加，但获得医疗保健专业副学士学位的比例没有增加。我们还发现学位获得情况在性别、种族/民族、家庭收入和10年级数学成绩方面存在差异。对MACC项目负责人的采访表明，供应限制阻碍了许多医疗保健副学士学位项目的扩展，但对STEM项目没有影响。

瞄准性别差距：分数与收入

Pelin Akyol, Kala Krishna, and Sergey Lychagin #33074

Abstract: Using data from the Turkish University Entrance Exam, we investigate the extent of the gender gap in college placement, its underlying causes, and potential policy interventions. We estimate preferences using a novel approach which improves our ability to capture substitution patterns and find clear evidence that placement differences are primarily driven by preference differences across gender. We compare stipend subsidies to score bonuses that achieve gender parity. Score subsidies improve the welfare of women almost entirely at the cost of men with similar scores and favor high-income women. Stipend subsidies improve the welfare of women, but at little cost to men and favor low-income women. Our work is the first to show that how gender neutrality is achieved matters to society.

摘要：我们利用土耳其大学入学考试的数据，研究大学录取中的性别差距程度、其根本原因以及可能的政策干预措施。我们采用一种新方法来估计偏好，从而更好地捕捉替代模式，发现录取差异主要由性别之间的偏好差异驱动。我们将实现性别平等的助学金补贴与分数加成进行了比较。分数补贴几乎完全以与女性分数相似的男性的福利为代价来提高女性福利，并偏向于高收入女性；而助学金补贴则在不显著影响男性的情况下改善了女性福利，并更有利于低收入女性。我们的研究首次表明，实现性别中立的方式对社会有重要影响。

“史上最大气候支出法案”有多大？影响《通胀削减法案》清洁能源影响的关键因素

Joseph E. Aldy #33092

Abstract: The Inflation Reduction Act could deliver more than $1 trillion in tax expenditures and outlays targeting clean energy deployment, but considerable uncertainty characterizes the economic, emissions, energy, and fiscal implications of the law. I review the features of the political system governing implementation, the regulatory system overlaying performance standards, the innovation responding to IRA incentives, and the energy networks in which IRA-supported investments operate to identify the key factors influencing IRA’s outcomes. Drawing from past research and policy experience, I illustrate how these factors could play out and how future program evaluation could reduce uncertainty and inform better climate policy.

摘要：《通胀削减法案》可能在清洁能源部署方面带来超过 1 万亿美元的税收支出和拨款，但该法案的经济、排放、能源和财政影响存在相当大的不确定性。本文回顾了管理实施的政治体系、叠加在绩效标准之上的监管体系、对《通胀削减法案》激励措施作出响应的创新，以及《通胀削减法案》支持的投资所依托的能源网络，从而确定影响其结果的关键因素。通过借鉴以往的研究和政策经验，我展示了这些因素可能如何发挥作用，并说明未来的项目评估如何减少不确定性，以帮助制定更好的气候政策。

往期精选：

      重磅：学术财经•学术笔记全汇总

重磅：学术财经全球价值链专题学术笔记大汇总（附下载链接失效学术笔记推文）

重磅| 基金申请内部学习和交流

【学术笔记·第37篇】风险和全球供应链：我们知道什么和我们需要知道什么

【学术笔记·第36篇】各有所长：全球供应链风险敞口（Exposure）测度

【学术笔记·第35篇】日本生产者价格指数理论与实证：最终需求-中间需求加总系统

【学术笔记·第34篇】北美自由贸易的贸易和福利影响估计

【学术笔记 第33篇】 英属印度时期铁路：交通基础设施的影响评估（AER）

【学术笔记 第32篇】 技术、地理和贸易(经典EK模型）

【学术笔记 第31篇】2018年贸易战对美国物价和福利的影响

【学术笔记 第30篇】全球价值链和国家部门层面实际有效汇率