Green bonds are seen as a key instrument to unlock climate finance. While their volume has grown steadily in recent years, the impact of the ‘green’ label on the bond market is poorly understood. Here, we investigate the differences between the yield term structures of green and conventional bonds in the US municipal bond market. We show that, although returns on conventional bonds are on average higher than for green bonds, the differences can largely be explained by the fundamental properties of the bonds. Historically, green bonds have been penalized on the municipal market, being traded at lower prices and higher yields than expected by their credit profiles. In recent years, however, the credit quality of municipal green bonds has increased and the premium turned positive. Green bonds are thus becoming an increasingly attractive investment, with scope to bridge the climate finance gap for mitigation and adaptation.
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Buchner, B. et al. The Global Landscape of Climate Finance 2014 (Climate Policy Initiative, 2014).
Bredenkamp, H. & Pattillo, C. Financing the Response to Climate Change. Note SPN10/06 25 (IMF, 2010).
Mathews, J. A., Kidney, S., Mallon, K. & Hughes, M. Mobilizing private finance to drive an energy industrial revolution. Energy Policy 38, 3263–3265 (2010).
Hamilton, K. Unlocking Finance for Clean Energy: The Need for ‘Investment Grade’ Policy (Chatham House, London, 2009).
Green Bond Principles, 2016: Voluntary Process Guidelines for Issuing Green Bonds (International Capital Market Association, 2016). http://www.icmagroup.org/assets/documents/Regulatory/Green-Bonds/GBP-2016-Final-16-June-2016.pdf
Green Bonds: Country Experiences, Barriers and Options (United Nations Environment Programme, 2016).
Clapp, C., Alfsen, K. H., Lund, H. F. & Pillay, K. Green Bonds and Environmental Integrity: Insights from CICERO Second Opinions Policy Note 2016: 01 (CICERO, 2016).
Summary of Green Bond Database Providers (GBP Databases and Indices Working Group, International Capital Market Association, 2017) https://www.icmagroup.org/assets/documents/Regulatory/Green-Bonds/Green-Bond-Databases-Summary-Document-190617.pdf
BNEF Bloomberg Terminal Guide (Bloomberg New Energy Finance, 2015); https://data.bloomberglp.com/bnef/sites/4/2015/09/BNEF_Green-Bonds-Terminal-Guide_H2-2015-update.pdf
World Bank Green Bonds (World Bank, accessed 29 September 2017); http://treasury.worldbank.org/cmd/htm/WorldBankGreenBonds.html.
Blinder, A. S. Wage discrimination: reduced form and structural estimates. J. Hum. Resour. 8, 436–455 (1973).
Oaxaca, R. Male–female wage differentials in urban labor markets. Int. Econ. Rev. 14, 693–709 (1973).
Zerbib, O. D. The Green Bond Premium. SSRN Working paper 2889690 (2017), https://dx.doi.org/10.2139/ssrn.2889690.
Svensson, L. Estimating and Interpreting Forward Interest Rates: Sweden 1992–1994. Working Paper 48711994 (National Bureau of Economic Research, 1994); https://ideas.repec.org/p/fth/stocin/579.html
Jansson, M. & Biel, A. Motives to engage in sustainable investment: a comparison between institutional and private investors. Sustain. Dev. 19, 135–142 (2011).
Lam, P. T. & Law, A. O. Crowdfunding for renewable and sustainable energy projects: An exploratory case study approach. Renew. Sustain. Energy Rev. 60, 11–20 (2016).
Kidney, S. Bonds 2015 Year-end Review (Climate Bond Initiative, London, 2016).
Getter, D. E. & Raj, G. The Demand for Municipal Bonds: Issues for Congress. Congressional Research Service Report (CRS, Washington, DC, 2015).
Hayes, P. & Schwartz, J. Market Myths and Realities (Blackrock, New York, 2013).
Electronic Municipal Market Access (Municipal Securities Rulemaking Board, accessed 25 September 2017); http://emma.msrb.org.
MSRB Rule Book (MSRB, 2017, accessed 24 February 2017); http://www.msrb.org/msrb1/pdfs/MSRB-Rule-Book-PDF-Current-Quarter.pdf.
Bond Credit Rating (Wikipedia, accessed 29 September 2017); https://en.wikipedia.org/wiki/Bond_credit_rating.
Kroll Bond Rating Agency (Wikipedia, accessed 29 September 2017); https://en.wikipedia.org/wiki/Kroll_Bond_Rating_Agency.
States Census Bureau (United States Census Bureau, 2016, accessed 24 February 2017); https://www.census.gov.
Rate Statistics (US Department of the Treasury, 2016, accessed 24 February 2017). https://www.treasury.gov/resource-center/data-chart-center/interest-rates/Pages/default.aspx.
Ametrano, F. & Ballabio, L. Quantlib — A Free/Open-Source Library for Quantitative Finance. Accessed 24 February 2017. http://quantlib.org/.
Neumark, D. Employers’ discriminatory behavior and the estimation of wage discrimination. J. Hum. Resour. 23, 279–295 (1988).
Powers, D. A., Yoshioka, H. & Yun, M.-S. mvdcmp: Multivariate decomposition for nonlinear response models. Stata 11, 556–576 (2011).
Jann, B. et al. The Blinder–Oaxaca decomposition for linear regression models. Stata 8, 453–479 (2008).
Reimers, C. W. Labor market discrimination against hispanic and black men. Rev. Econ. Stat. 65, 570–579 (1983).
Cotton, J. On the decomposition of wage differentials. Rev. Econ. Stat. 70, 236–243 (1988).
Yun, M.-S. Decomposing differences in the first moment. Econ. Lett. 82, 275–280 (2004).
Karpf, A. Data and Code for Municipal Green Bonds Analysis v1.0 (2017); http://dx.doi.org/10.5281/zenodo.1068519.
The authors acknowledge financial support from the Horizon 2020 research and innovation programme under grant agreement no. 640772 (DOLFINS) and no. 642018 (GREEN-WIN). We thank the PostgreSQL, QuantLib and Scrapy projects for making their software freely available. The authors are grateful to G. Capelle-Blancard who provided useful comments on a previous version of this manuscript.
The authors declare no competing financial interests.
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Karpf, A., Mandel, A. The changing value of the ‘green’ label on the US municipal bond market. Nature Clim Change 8, 161–165 (2018). https://doi.org/10.1038/s41558-017-0062-0
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