The impacts of global economic policy uncertainty on green bond returns: A systematic literature review

This study utilizes the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) framework to investigate the interconnectedness of green bond with various financial markets, aiming to clarify their relationship with global economic uncertainty and their impact on returns. After a comprehensive search of pertinent research papers from January 2016 to September 2023, 79 relevant articles were identified. The analysis delves into the evolution of research on green bonds' interactions with economic policy uncertainty considering the financial markets, analytical methodologies, contributions to the field, and the role of green bonds under both normal and extreme market conditions. The study reveals noteworthy findings: firstly, the interplay between green bonds and financial markets is influenced by macroeconomic factors, such as the COVID-19 pandemic and the Russia-Ukraine conflict in 2022, which were significant sources of economic policy uncertainty during the study period. Secondly, during times of global economic uncertainties, green Bonds act as net transmitters of spillovers in the short term but shifts to net receivers in the long term, positioning them as strategic hedging assets rather than safe-havens, particularly against spillovers from crude oil and CO2 emission in times of economic uncertainties. Additionally, the review highlights prevalent methodologies employed to assess the relationship between global economic policy uncertainty and green bonds. Some of which include quantile approaches, the Diebold & Yilmaz 2012 spillover index, as well as various models like VAR models, GARCH models, ARDL models. Notably, certain countries like China, the United Kingdom, and Vietnam emerge as key contributors to this research domain. The review not only consolidates existing knowledge but also provides valuable insights for investors and policymakers regarding green bonds in terms of risk management and asset allocation, while also pointing towards potential avenues for future research in this field.