01
原文：Fukang Chen, Minhao Chen, Lin William Cong, Haoyu Gao, and Jacopo Ponticelli. Pricing the Priceless: The Financial Cost of Biodiversity Conservation. NBER Working Paper(2024). https://www.nber.org/papers/w32743
Pricing the Priceless: The Financial Cost of Biodiversity Conservation
ABSTRACT: The pace of biodiversity loss requires drastic shifts in conservation efforts that carry substantial costs. We investigate how the financial market prices such conservation costs exploiting the "Green Shield Action," a major regulatory initiative launched by the Chinese central government in 2017 to enforce biodiversity preservation rules in national nature reserves. We document that, while improving local biodiversity, the initiative led to a significant increase in bond yields for Chinese municipalities with national nature reserves. Evidence suggests that these effects are driven by expected increases in transition costs resulting from shutting down illegal economic activities within reserves and local public spending on biodiversity following the initiative. Overall, our results indicate that investors show little consideration beyond financial payoffs towards endeavors counteracting biodiversity loss.
为无价定价: 保护生物多样性的融资成本
摘要：生物多样性损失的速度要求在保护工作中进行剧烈的转变，这些转变伴随着显著的成本。文章旨在探讨金融市场如何定价这些保护成本，并借助于中国中央政府2017年实施的“绿盾行动”(Green Shield Action)这一重要监管政策，该政策旨在强化国家自然保护区内生物多样性保护规则的执行。文章研究结果表明，尽管该举措有助于提升地方生物多样性，但却导致拥有国家自然保护区的中国市政债券收益率显著上升。证据表明，这一现象主要源于因关闭保护区内的非法经济活动和后续地方在生物多样性上的公共支出导致的预期过渡成本的增加。总体而言，文章的研究结果表明，投资者在应对生物多样性损失的行动上，除了财务回报外，很少考虑其他方面。
亮点：（1）研究问题新颖独特。文章研究以“绿盾计划”为外生冲击，采用DID的研究方法探究生物多样性保护的市场反应，并聚焦于国家自然保护区的实施对市政债券收益率的影响作用；（2）在机制分析中，作者运用遥感数据和夜间灯光数据阐述非法经济活动的减少，通过对政府采购合同的文本分析阐述与自然保护区相关的成本增加；（3）不同于公司层面研究，文章选取国家层面分析，避免了公司选址和搬迁的自选择问题；（4）文章分析的市政债券并非为生物多样性而发布，未能排除政府公信度本身的影响，作者从政府融资约束和地方官员政治风险的视角进行检验；（5）在经济后果分析中，作者运用鸟类勘测数据探究绿盾计划对自然环境保护的实际影响作用，运用生物多样性的新闻报道探究投资者信息不对称的影响。
02
原文：Stefano Giglio, Theresa Kuchler, Johannes Stroebel, and Xuran Zeng. Biodiversity Risk. NBER Working Paper(2023). https://www.nber.org/papers/w31137
Biodiversity Risk
ABSTRACT: We explore the effects of physical and regulatory risks related to biodiversity loss on economic activity and asset values. We first develop a news-based measure of aggregate biodiversity risk and analyze how it varies over time. We also construct and publicly release several firm-level measures of exposure to biodiversity risk, based on textual analyses of firms’ 10-K statements, a large survey of financial professionals, regulators, and academics, and the holdings of biodiversity-related funds. Exposures to biodiversity risk vary substantially across industries in a way that is economically sensible and distinct from exposures to climate risk. We find evidence that biodiversity risks already affect equity prices: returns of portfolios that are sorted on our measures of biodiversity risk exposure covary positively with innovations in aggregate biodiversity risk. However, our survey indicates that market participants do not perceive the current pricing of biodiversity risks to be adequate.
生物多样性风险
摘要：文章探讨了与生物多样性损失相关的物理风险和监管风险对经济活动和资产价值的影响。首先，文章开发了基于新闻的综合生物多样性风险度量指标，并分析其随时间的变化。同时通过分析公司10-K报告、大规模的金融专业人士、监管机构和学者的调查，以及与生物多样性相关基金的持股情况，构建并公开发布几种基于文本分析的公司层面生物多样性风险的度量指标。不同行业的生物多样性风险存在显著差异，这种差异在经济上是合理的，并且与气候风险有所区别。文章研究发现，生物多样性风险已经影响股票价格：根据构建的生物多样性风险衡量指标排序后的投资组合回报与综合生物多样性风险的创新呈正相关关系。然而，文章调查显示，市场参与者未能充分考虑对生物多样性风险的定价。
亮点：（1）通过问卷调查和媒体报道，作者验证了生物多样性风险和气候风险是两种不同的风险；（2）作者基于美国公司的10-K文件采用文本分析的研究方法构建衡量公司层面的生物多样性风险指标，并对外公开相关数据供其他学者借鉴采用；（3）作者基于学者、机构等调查进一步分析行业层面的生物多样性风险；（4）作者分析了生物多样性相关基金的持股情况探究市场反应。
03
原文：Stefano Giglio, Theresa Kuchler, Johannes Stroebel, and Olivier Wang. The Economics of Biodiversity Loss. NBER Working Paper(2024).
https://www.nber.org/papers/w32678
The Economics of Biodiversity Loss
ABSTRACT: We explore the economic effects of biodiversity loss by developing an ecologically-founded model that captures how different species interact to deliver the ecosystem services that complement other factors of economic production. Aggregate ecosystem services are produced by combining several non-substitutable ecosystem functions such as pollination and water filtration, which are each provided by many substitutable species playing similar roles. As a result, economic output is an increasing but highly concave function of species richness. The marginal economic value of a species depends on three factors: (i) the number of similar species within its ecosystem function, (ii) the marginal importance of the affected function for overall ecosystem productivity, and (iii) the extent to which ecosystem services constrain economic output in each country. Using our framework, we derive expressions for the fragility of ecosystem service provision and its evolution over time, which depends, among other things, on the distribution of biodiversity losses across ecosystem functions. We discuss how these fragility measures can help policymakers assess the risks induced by biodiversity loss and prioritize conservation efforts. We also embed our model of ecosystem service production in a standard economic model to study optimal land use when land use raises output at the cost of reducing biodiversity. We find that even in settings where species loss does not reduce output substantially today, it lowers growth opportunities and reduces resilience to future species loss, especially when past species loss has been asymmetric across functions. Consistent with these predictions of our model, we show empirically that news about biodiversity loss increases spreads on credit default swaps (CDS) more for countries with more depleted ecosystems.
生物多样性损失的经济影响
摘要：文章通过开发一个基于生态学的模型探讨生物多样性损失的经济影响，该模型捕捉了不同物种如何相互作用以提供与其他经济生产要素相辅相成的生态系统服务。综合生态系统服务是通过结合多种不可替代的生态系统功能（如授粉和水过滤）来产生的，每个功能由许多扮演相似角色的可替代物种提供。因此，经济产出是一个物种丰富度的递增的高度凹函数。物种的边际经济价值取决于三个因素：（i）生态系统功能内相似物种的数量，（ii）受影响的功能对整体生态系统生产力的边际重要性，以及（iii）生态系统服务在各国经济产出中的约束程度。利用此框架，作者推导出生态系统服务供应的脆弱性及其随时间演变的表达式，这依赖于生态系统功能内生物多样性损失的分布等因素。作者讨论了这些脆弱性指标如何帮助政策制定者评估生物多样性损失带来的风险及保护工作的优先级。作者还将生态系统服务生产模型嵌入标准经济模型中研究以牺牲生物多样性为代价的最佳利用土地时的产出。作者发现，即使在当前物种损失并未显著减少产出的情况下，物种损失会降低未来物种损失的增长机会和韧性，特别是在过去物种损失在功能上不对称的情况下。与作者的模型预测一致，实证表明在生态系统较为匮乏的国家中，关于生物多样性损失的新闻消息增加信用违约掉期(credit default swaps)的利差。
亮点：（1）作者构建模型量化分析生物多样性损失带来的经济影响；（2）作者清晰阐述了综合生态系统服务中影响物种边际经济价值的三个因素，帮助理解物种多样性损失的经济风险；（3）基于模型作者构建了衡量生态系统服务脆弱性的度量指标，即总体生态系统服务产出对生物多样性冲击的敏感性；（4）作者选取国家层面信用违约掉期(credit default swaps)，实证分析了生物多样性损失对国家经济产出的影响。
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总编：游家兴
解析：司淑玉
审校：陈璐 孙倩
编辑：潘芳妍
