气候与冲突经济学的新证据

Marshall Burke, Joel Ferguson, Solomon M. Hsiang, and Edward Miguel #33040

Abstract: We survey the quantitative research literature linking climate and conflict, a body of research that spans multiple academic disciplines and has roughly doubled in size in the last decade. It makes three main contributions. First, we carry out a meta-analysis – updating Hsiang et al (2013) and Burke et al (2015) with a far larger sample – and confirm that extreme climate is associated with elevated risk of inter-group conflict, intra-personal violence, and self-harm. The estimated average effects are smaller than the earlier estimates, although they remain meaningful in magnitude and highly statistically significant. Second, we present a methodological discussion and empirical illustration of how the use of data at different spatial and temporal scales can affect these results. Third, we discuss specific studies that present evidence on the mechanisms underlying this relationship including: (1) economic conditions, income, and agricultural productivity; (2) socio-demographic factors; (3) migration and transportation costs; (4) policy, politics and institutions; and (5) psychological and physiological factors. The chapter concludes with a discussion of policy implications and some open questions.

摘要：我们综述了将气候与冲突联系起来的定量研究文献，这一研究领域跨越多个学术学科，并在过去十年里大约翻了一番。本文做出了三项主要贡献。首先，我们进行了元分析——更新了Hsiang等（2013）和Burke等（2015）的研究，使用了更大的样本——并确认极端气候与群体间冲突、个人暴力以及自残风险的增加有关。尽管估计的平均效应比之前的研究要小，但其影响在规模上仍然具有重要意义，并且在统计上高度显著。其次，我们进行了一场方法论讨论，并通过实证说明了使用不同空间和时间尺度的数据如何影响这些结果。第三，我们讨论了几项具体研究，这些研究提供了关于这一关系背后的机制的证据，包括：(1) 经济状况、收入和农业生产力；(2) 社会人口因素；(3) 移民和运输成本；(4) 政策、政治和制度；以及(5) 心理和生理因素。本文最后讨论了政策意义及一些尚未解决的问题。

健康保险与兼职就业：平价医疗法案的影响

Katharine G. Abraham and Henry S. Farber #33046

Abstract: Prior to the passage of the Affordable Care Act (ACA), part-time workers were much less likely than full-time workers to have health insurance. The ACA included multiple provisions intended to raise health insurance coverage rates, including a mandate that employers provide affordable coverage to full-time workers, a requirement that dependents be allowed to remain on their parents’ plan until age 26, extensions of Medicaid coverage, and the establishment of health insurance exchanges on which lower-income households could purchase subsidized coverage. Implementation of these provisions was associated with a decline in the full-time/part-time coverage gap from 6.5 percentage points in 2013 to 3.1 percentage points in 2021. Increases in Medicaid coverage and insurance purchased on the exchanges reduced were the largest contributors to the reduction in the full-time/part-time coverage gap.

摘要：在《平价医疗法案》（Affordable Care Act, ACA）通过之前，兼职工人相比全职工人获得健康保险的可能性要小得多。ACA包含多项旨在提高健康保险覆盖率的条款，包括要求雇主为全职员工提供负担得起的保险、允许26岁以下的受抚养人继续留在父母的保险计划中、扩大医疗补助（Medicaid）覆盖范围，以及建立健康保险交易所，低收入家庭可以在这些交易所购买有补贴的保险。这些条款的实施使全职和兼职员工的保险覆盖差距从2013年的6.5个百分点下降到2021年的3.1个百分点。医疗补助覆盖的增加和通过交易所购买的保险是缩小全职与兼职员工保险覆盖差距的最大贡献因素。

平台权力的博弈：Spotify与主要唱片公司

Luis Aguiar, Joel Waldfogel, and Axel Zeijen #33048

Abstract: Digitization has facilitated the emergence of large distribution platforms downstream from traditionally powerful suppliers. Digital platforms can carry many suppliers’ products, test the products’ consumer appeal, and choose which products to promote, potentially shifting power from the suppliers to the platforms. We study these forces in the recorded music industry, which was traditionally dominated by a few “major” record labels distributing their products through fragmented radio stations and retailers. Now, the majors receive most of their promotion and distribution through platforms like Spotify, which carry millions of songs from both major and “independent” suppliers. We study Spotify’s use of playlists using data covering 2017-2020. First, Spotify used their expanded playlist capacity to test – and discover – proportionately more independent songs to promote on their playlists. Second, at least relative to major-label playlists, Spotify-operated playlists promoted new independent songs more than was indicated by their subsequent success. Third, placement on Spotify new-music playlists has a large causal impact on streams. The independent-label share of new-music promotion rose from 38 percent in late 2017 to 55 percent in early 2020, which helps to explain the reported decline in the share of Spotify royalty payments to major-label suppliers over the same period.

摘要：数字化促进了大型分销平台的兴起，这些平台位于传统上强大的供应商的下游。数字平台可以承载多个供应商的产品，测试这些产品的消费者吸引力，并选择推广哪些产品，可能导致权力从供应商向平台转移。我们研究了这些力量在录制音乐行业中的表现，该行业传统上由少数几家“主要”唱片公司主导，它们通过分散的广播电台和零售商分发产品。如今，这些主要唱片公司的大部分宣传和分销都是通过像Spotify这样的平台进行的，这些平台承载了来自主要和“独立”供应商的数百万首歌曲。我们研究了Spotify在2017年至2020年期间使用播放列表的数据。首先，Spotify利用其扩展的播放列表容量，测试并发现了更多比例的独立歌曲进行推广。其次，至少相对于主要唱片公司管理的播放列表而言，Spotify运营的播放列表推广了更多的新独立歌曲，超出了这些歌曲后续成功的预期。第三，出现在Spotify的新音乐播放列表中对播放量有着巨大的因果影响。独立唱片公司在新音乐推广中的份额从2017年底的38%上升到2020年初的55%，这有助于解释同期Spotify向主要唱片供应商支付版税份额下降的现象。

贫困、困境与政府转移支付

Bruce D. Meyer, Jeehoon Han, and James X. Sullivan #33052

Abstract: We examine how the well-being of those with few resources changed, amidst economic disruption and large, transitory government transfers. We find that in the years leading up to the pandemic and in 2020, the patterns for income and consumption poverty were very similar. In 2021 and 2022, however, changes in income and consumption poverty were quite different—consumption poverty fell less than income poverty in 2021, and then income poverty rose sharply in 2022 while consumption poverty continued to decline. Reports of hardships rose in 2022 for both families with and without children, suggesting increased concern about financial well-being as COVID-era transfer programs expired. A key difference between income and consumption measures appears to be saving during the pandemic followed by dissaving, even among those near the poverty line. This finding indicates that permanent income models can even be relevant when low-income households, that typically have very limited saving, receive very large transitory payments. Unlike past academic studies and numerous politicians and pundits that have attributed most of the decline in income poverty in 2021, and its subsequent rise in 2022, to the Child Tax Credit, we show that expanded Unemployment Insurance and stimulus payments played a larger role.

摘要：我们研究了在经济动荡和大规模临时政府转移支付的背景下，资源匮乏人群的福祉如何变化。我们发现，在疫情爆发前的几年以及2020年，收入和消费贫困的模式非常相似。然而，2021年和2022年的收入与消费贫困的变化有明显差异——2021年消费贫困的下降幅度小于收入贫困，而2022年收入贫困急剧上升，而消费贫困则继续下降。2022年，无论是有孩子的家庭还是没有孩子的家庭，困境报告都在增加，表明随着疫情期间的转移支付项目到期，人们对财务状况的担忧加剧。收入和消费之间的一个关键差异似乎是疫情期间的储蓄行为以及随后出现的去储蓄现象，甚至在接近贫困线的人群中也出现了这种情况。该发现表明，即使是通常储蓄能力有限的低收入家庭，在获得非常大规模的临时支付时，永久收入模型也具有相关性。与许多过去的学术研究以及众多政治家和评论家将2021年收入贫困的下降和2022年的上升主要归因于儿童税收抵免（Child Tax Credit）的观点不同，我们的研究显示，扩展的失业保险和刺激性支付对这一变化发挥了更大的作用。。

经济松弛与经济发展

Michael W. Walker, Nachiket Shah, Edward Miguel, Dennis Egger, Felix Samy Soliman, and Tilman Graff #33055

Abstract: Slack – the underutilization of factors of production – varies systematically with economic development. Using novel and detailed measures of the utilization of labor and capital from a large representative sample of firms in rural and urban Kenya, we show that utilization is increasing in firm size, market access, and economic activity. We present a model of firm capacity choice where indivisibility in at least one input is a key driver of slack. We embed the model in spatial general equilibrium, with features characteristic of low-income settings – including many small firms and high transport costs – and show that it rationalizes both the endogenous emergence of slack in steady-state and elastic aggregate supply curves. We empirically validate model predictions using reduced-form estimates of the general equilibrium effects of cash transfers from a large-scale RCT in Kenya. The parsimonious model replicates much of the experimental evidence, predicting a large real multiplier of 1.5, driven by expansion in low-utilization sectors and firms, and limited average price inflation. Counterfactual analyses indicate that multipliers are likely to be meaningfully smaller in lower slack settings, such as urban areas. We use the model to revisit the estimation of spatial spillovers in clustered RCTs and uncover non-trivial ’missing intercept’ effects on income and inflation. Additionally, we innovate methodologically by pre-registering key elements of model estimation and validation. The findings suggest that input indivisibilities and slack are key features of developing country settings, and are quantitatively important for macroeconomic dynamics and policies.

摘要：生产要素的未充分利用（即“松弛”）随着经济发展水平的不同而系统性变化。通过对肯尼亚农村和城市的大型代表性样本企业的劳动力和资本利用率进行新颖而详细的衡量，我们发现，企业的利用率随着企业规模、市场准入和经济活动的增加而上升。我们提出了一个企业产能选择的模型，其中至少一个投入的不可分性是导致松弛的关键因素。我们将该模型嵌入到空间一般均衡框架中，并加入低收入环境的特征——包括众多小型企业和高运输成本——展示了在稳态下松弛的内生出现和富有弹性的总供给曲线。通过肯尼亚一项大规模随机对照试验（RCT）中的现金转移支付的一般均衡效应的简化形式估计，我们实证验证了模型预测。简明的模型再现了大量实验证据，预测了一个较大的实际乘数效应（1.5倍），主要由低利用率部门和企业的扩展推动，且平均价格通胀有限。反事实分析表明，在低松弛度的环境（如城市地区），乘数效应可能会显著缩小。我们利用该模型重新审视了集群RCT中空间溢出效应的估算，并揭示了收入和通胀上的非平凡“缺失截距”效应。此外，我们在方法上进行创新，预先注册了模型估算和验证的关键要素。研究结果表明，投入不可分性和松弛是发展中国家环境中的关键特征，对于宏观经济动态和政策具有重要的定量意义。

论企业家的本质

Anmol Bhandari, Tobey Kass, Thomas J. May, Ellen McGrattan, and Evan Schulz #32948

Abstract: This paper provides new insights into the nature of entrepreneurship using a novel panel dataset based on U.S. administrative data from the Internal Revenue Service and the Social Security Administration. These data are used to analyze patterns of income growth and determinants of entrepreneurial choice for a large population of business owners. Earlier studies relying on household survey data have been limited by small samples, short panels, and income top-coding and, as a result, have focused on the typical self-employed individual rather than the typical dollar earned in self-employment. Without these limitations, we find that self-employed individuals have significantly higher average income and steeper, more persistent income growth profiles than paid- employed peers with similar characteristics. Contrary to the survey evidence, we find a much smaller role for non-pecuniary motives in driving entrepreneurial choice and little evidence for inordinately high risk factors or startup costs impeding entry. Linking individual and business filings, we find that business founders have sufficient resources in the initial years of operation to ensure positive individual income despite the fact that most claim a loss on the business.

摘要：本文利用基于美国国税局（IRS）和社会保障局（SSA）行政数据的新型面板数据集，为企业家精神的本质提供了新的见解。这些数据被用于分析大量企业主的收入增长模式及其创业选择的决定因素。早期依赖于家庭调查数据的研究受限于样本量小、面板期短以及收入上限编码，因此重点关注的是典型的自雇个体，而非自雇收入的典型情况。在没有这些限制的情况下，我们发现自雇个体的平均收入显著高于具有相似特征的受薪雇员，且其收入增长曲线更陡峭、持续性更强。与调查证据相反，我们发现非货币动机在推动创业选择中的作用较小，且几乎没有证据表明过高的风险因素或启动成本阻碍了创业进入。通过将个人和企业申报数据相连接，我们发现企业创始人在运营初期有足够的资源确保个人收入为正，尽管大多数人在企业方面申报了亏损。

产业政策：来自造船业的经验教训 

Panle Jia Barwick, Myrto Kalouptsidi, and Nahim B. Zahur #33043

Abstract: Industrial policy has been used throughout history in some form or other by most countries. Yet, it remains one of the most contentious issues among policymakers and economists alike. In part, this is because the empirical evidence on whether and how it should be implemented remains slim. Scant data on government subsidies, conflicting theoretical arguments, and the need to account for governments’ short and long-run objectives, render research particularly challenging. In this article, we outline a theory-based empirical methodology that relies on estimating an industry equilibrium model to measure hidden subsidies, assess their welfare consequences for the domestic and global economy, as well as evaluate the effectiveness of different policy designs. We illustrate this approach using the global shipbuilding industry as a prototypical example of an industry targeted by industrial policy, especially in periods of heavy industrialization. Just in the past century, Europe, followed by Japan, then South Korea, and more recently China, developed national shipbuilding programs to propel their firms to global leaders. Success has been mixed across programs, certainly by welfare metrics, and sometimes even by growth metrics. We use our methodology on China to dissect the impact of such programs, what made them more or less successful, and how we can justify why governments have chosen shipbuilding as a targe.

摘要：产业政策在历史上以某种形式被大多数国家使用。然而，它仍然是政策制定者和经济学家之间最具争议的问题之一。部分原因在于，关于是否以及如何实施产业政策的实证证据仍然有限。关于政府补贴的数据稀缺、理论上的冲突，以及需要平衡政府的短期和长期目标，使得相关研究尤其具有挑战性。在本文中，我们概述了一种基于理论的实证方法，依赖于估计行业均衡模型来衡量隐藏补贴，评估其对国内和全球经济的福利影响，以及评估不同政策设计的有效性。我们以全球造船业为典型例子来展示这一方法，造船业在许多重工业化时期常常成为产业政策的目标。在过去的一个世纪里，欧洲、日本、韩国以及最近的中国，都制定了国家造船计划，以推动其企业成为全球领军者。各项计划的成功程度不同，尤其在福利指标上有差异，有时甚至在增长指标上也不尽相同。我们运用这一方法来分析中国的造船计划，剖析这些计划的影响、它们成功或不成功的因素，以及如何解释政府选择造船业作为目标的原因。

金融复杂性与银行市场力量

Matthias Fleckenstein and Francis A. Longstaff #33049

Abstract: We study the relation between bank funding costs and the financial sophistication of bank customers. In doing this, we make use of a natural experiment that allows us to identify banks that—either intentionally or unintentionally—price time deposits in a way that can result in financially-unsophisticated customers essentially being shortchanged. We find that these banks have significantly lower deposit funding costs. These results provide evidence that having financially-unsophisticated customers may provide banks with substantial market power and be an important component of the value of a bank's deposit franchise.

摘要：我们研究了银行资金成本与客户金融复杂性之间的关系。在此过程中，我们利用了一项自然实验，该实验使我们能够识别那些——无论是有意还是无意——以一种可能导致金融不够复杂的客户利益受损的方式定价定期存款的银行。研究发现，这些银行的存款资金成本显著较低。这些结果表明，拥有金融不够复杂的客户可能为银行提供了显著的市场力量，并且可能是银行存款业务价值的重要组成部分。

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