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听说了吗?环境政策与清洁投资

Heard the news? Environmental policy and clean investments
Journal of Public Economics · 2024 · Joëlle Noailly、Laura Nowzohour、Matthias van den Heuvel、Ireneu Pla

中文摘要

我们构建了首个基于新闻的美国环境与气候政策指数,并考察其与清洁投资的关系。我们从过去四十年间美国十家主流报纸中提取文本,运用文本挖掘技术,构建了涵盖1981—2019年、细粒度的美国环境与气候政策新闻指数(EnvP)。此外,我们还构建了一系列补充指标,包括环境政策情绪指数以及多个特定主题指数。我们通过以下方式验证该指数:证明其能够准确捕捉美国环境与气候政策演变的趋势与峰值,并且与清洁投资存在具有实质意义的关联,这与环境法规为清洁市场带来日益增长的机会相一致。在企业层面的估计中,我们发现,该指数与清洁技术初创企业获得风险投资(VC)融资的概率上升相关,也与受环境法规影响最大的高排放企业股票收益率下降相关。在总量层面,我们通过VAR模型发现,基于新闻的可再生能源政策指数受到冲击,与清洁能源风险投资交易数量增加以及某基准清洁能源交易型开放式指数基金(ETF)的管理资产增加相关。• 我们构建了EnvP指数——首个基于新闻的美国环境与气候政策指数,提供1981—2019年的月度数据。• 我们的方法将文本挖掘机器学习技术应用于美国十家主流报纸的文章。• 我们还构建了一个情绪指数和25个环境与气候政策特定主题指数。• EnvP指数与清洁市场投资存在具有实质意义的关联。

Abstract

We build the first news-based index of US environmental and climate policy and examine how it relates to clean investments. Extracting text from ten leading US newspapers over the last four decades, we use text-mining techniques to develop a granular news index of US environmental and climate policy (EnvP) over the 1981–2019 period. Furthermore, we develop a set of additional measures, namely an index of sentiment on environmental policy, as well as various topic-specific indexes. We validate our index by showing that it correctly captures trends and peaks in the evolution of US environmental and climate policy and that it has a meaningful association with clean investments, in line with environmental regulations supporting growing opportunities for clean markets. In firm-level estimations, we find that our index is associated with a greater probability of receiving venture capital (VC) funding for cleantech startups and reduced stock returns for high-emissions firms most exposed to environmental regulations. At the aggregate level, we find in VAR models that a shock in our news-based index of renewable energy policy is associated with an increase in the number of clean energy VC deals and in the assets under management of a benchmark clean energy exchange-traded fund. • We build the EnvP index - the first news-based index of US environmental and climate policy, available on a monthly basis over the 1981–2019 period. • Our method applies text-mining machine learning techniques to articles from ten leading US newspapers. • We also develop an index of sentiment and 25 topic-specific indexes of environmental and climate policy. • The EnvP index has a meaningful association with investments in clean markets.
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