2.1.1. Green Commitment
Green bond issuance represents the green commitment by a corporation to improve its environmental performance. First, as stated in the green bond prospectuses and frameworks, corporations are committing to invest significant amounts of funds in green projects by issuing green bonds. Second, to ensure that these funds are actually spent on these green projects, green bonds are usually certified by independent rating institutions, such as JCR, R&I, DNV, Sustainalytics, etc. Unlike traditional bond ratings, independent institution ratings of green bonds focus on the following aspects: use and management of proceeds, green project evaluation and selection process, environmental performance reporting, and green project completion. Third, according to the Green Bond and Sustainability-Linked Bond Guidelines, although there are no principal requirements for issuing green bonds, the guidelines recommend that corporations set specific, quantitative KPIs and SPTs and report annually on their achievements. Thus, green bond issuance can encourage corporations to promote their green commitments and enhance their environmental management capabilities, contributing to improving their environmental performance. Previous research confirms the direct or indirect impact of corporate green commitment, green management, and green training for employees on improving corporate environmental performance (
Haldorai et al., 2022;
Joshi & Dhar, 2020;
Sharma et al., 2021;
Zhu & Sarkis, 2004).
In addition to the widely publicized GHG emissions, the reduction in energy consumption is also an important issue for sustainable development. According to the Sustainable Development Goals Report 2023 published by the United Nations (UN), achieving global energy efficiency goals still requires substantial progress (
UN, 2008). The average annual increase in global primary energy intensity from 2015 to 2020 is 1.4%, which is far below the 2.6% required to achieve the SDGs targets. Hence, in order to compensate for the lost time, energy intensity must increase by an average of 3.4% per year until 2030. According to the International Energy Agency (IEA), energy consumption intensity is often used as an indicator of energy efficiency because it essentially captures a proxy measure of energy demand (
IEA, 2021). As a major manufacturing country, Japan has also implemented a series of policies in recent years to control the energy consumption of corporations. According to the Japan Natural Resources and Energy Agency, corporations with annual energy consumption of at least 1.5 million liters (oil equivalent) are obliged to implement an energy management system, report annual energy consumption, and submit energy efficiency plans (
METI, 2022).
Although reducing energy consumption is crucial to achieving the SDGs, the existing literature has concentrated on the relationship between green bond issuance and other measures of corporate environmental performance, while ignoring energy consumption.
Lian et al. (
2024) use data from non-financial listed firms in China between 2010 and 2020 and find that green bond issuance can alleviate corporate financing constraints and enhance corporate green innovation capabilities, thus playing a positive role in achieving environmental goals.
Kartal et al. (
2024) assess the role of green bonds in advancing carbon neutrality in China from 2019 to 2023, indicating that green bond issuance significantly reduces carbon emissions in the transport and international aviation sectors.
Luo and Lyu (
2024) suggest that the issuance of green bonds significantly enhances corporate environmental performance, particularly in labor-intensive firms, supporting the signaling role of green bonds.
Zhou and Cui (
2019) conduct an empirical study based on 144 green bonds issued in China between 2016 and 2019, and they find that the issuance of green bonds contributes to the improvement in the Corporate Social Responsibility (CSR) score.
Xu et al. (
2023) point out that green credit reduces corporate carbon emission intensity by strengthening environmental supervision. They emphasize the importance of quantitative and standardized corporate environmental information disclosure for green finance in reducing carbon emissions.
Diaz-Sarachaga (
2021) also suggests that corporate sustainability reporting is poorly standardized and lacks comparability. The author highlights the importance of developing quantitative frameworks to standardize and measure business contributions to achieving the SDGs.
Flammer (
2021) states that independent third-party certification of green bonds is a solid corporate green commitment, emphasizing that only certified green bond issuance will improve the environmental performance of their issuers. In addition, only green projects financed by green bonds lead to improvements in corporate environmental performance, as the green bond issuance amount is too small relative to the size of corporate assets. Based on this, this study categorizes green projects into two types: GHG emission intensity reduction projects and energy consumption intensity reduction projects. Furthermore, while green bond issuers incorporate their specific quantitative environmental targets as a crucial part of their green commitments, little is known in this area.
Table A1 in
Appendix A reports the specific quantitative corporate environmental targets for these green projects, including GHG emissions reduction targets and energy consumption reduction targets. According to the prospectuses and frameworks of all 106 green bonds in the sample, 74 bonds have set targets to reduce GHG emissions, while only 30 bonds have set targets to reduce energy consumption. Since not all green bond issuers have set specific quantitative corporate environmental targets to reduce GHG emissions and energy consumption, this study proposes the following hypothesis:
Hypothesis 1. Issuing green bonds reduces GHG emissions intensity, especially for corporations that have set specific targets.
Hypothesis 2. Issuing green bonds reduces energy consumption intensity, especially for corporations that have set specific targets.
2.1.2. Signaling, Cost of Capital and Disclosure
Signaling theory focuses on how firms convey information about their qualities or characteristics to investors, consumers, or other stakeholders.
Spence (
1973) first suggests that, in the situation of information asymmetry, the party with more information has an incentive to convey information to the other party. Signals are considered credible if they are conveyed through observable behaviors or attributes that are costly or difficult to imitate. Corporations take a variety of actions to signal their quality by conveying credible information to investors. Several previous studies point out that the influence of green bond issuance on corporate financial performance can be examined through the framework of signaling theory due to the fact that investors lack sufficient information to assess a corporation’s commitment to environmental sustainability (
Flammer, 2021;
Lyon & Maxwell, 2011;
Lyon & Montgomery, 2015). From the investors’ perspective, green bond issuance sends a reliable signal, thus helping them to reliably distinguish between corporations that are genuinely committed to environmental goals and those that are not.
As discussed in
Section 2.1.1, green bond issuance constitutes a form of corporate commitment to environmental sustainability, which is a credible signal for investors. Using daily Google search activity and multiple green bond indices,
Pham and Huynh (
2020) reveal a dynamic feedback relationship between investor attention and green bond market performance. Some previous studies indicate that issuing green bonds leads to an increase in corporate stock prices.
Tang and Zhang (
2020) offer an empirical investigation of stock market reactions to corporate ESG initiatives. Their analysis shows a significant increase in issuers’ stock prices following the disclosure of green bond issues. Notably, the degree of response is more pronounced for first-time issuers than for recurring issuers and corporate entities, as opposed to financial institution issuers.
Zhou and Cui (
2019) indicate that green bond issuance announcements positively affect firm stock returns. They argue that the issuance of green bonds is a sign of sustainable development and environmental protection, and can enhance investor confidence. Furthermore, their study provides empirical evidence supporting the notion that green bond issuance contributes to enhancing corporate financial performance.
Flammer (
2021) provides evidence of a significant positive stock market response to green bond issuance, with a cumulative abnormal return of 0.49%. In contrast,
Lebelle et al. (
2020) point out that green bond issuance causes negative shocks to the stock market and emphasize that corporate green bonds are considered a sign of market uncertainty. According to their empirical evidence, green bond issuance announcements lead to a 0.2% to 0.5% decline in stock prices.
In addition, green bonds might become a more cost-effective source of financing if investors are willing to accept lower yields in pursuit of the broader objective of combating climate change. Previous studies suggest that green bonds can reduce the cost of capital for corporations, thereby affecting their financial performance.
Zhai et al. (
2022) analyze 1577 listed Chinese manufacturing firms from 2016 to 2020 and find that participation in ESG activities allows firms to attract more investors and reduce risk, resulting in a positive market response and lower cost of capital.
Li et al. (
2022) conduct a study on Chinese listed companies in pollution-intensive industries from 2014 to 2019, and find that firms with higher CSR performance have less operational risk and information asymmetry, thereby reducing their cost of capital. They also highlight the role of green credit in reducing the cost of capital for firms.
Baldi and Pandimiglio (
2022) investigate the impact of corporate ESG score and greenwashing risk on green bond yields, indicating that investors accept lower yields for impactful projects while demanding higher returns when greenwashing risk is high. Notably, they find that such risk is particularly elevated in manufacturing firms.
Zerbib (
2019) notes that the green bond label on corporate bonds reflects the issuer’s intention and responsibility to pursue environmentally responsible investment activities. This environmental commitment is certified through the issuance of green bonds and monitored by investors.
Agliardi and Agliardi (
2019) suggest that the issuance of green bonds confers a green label upon firms, enhancing their credibility in capital markets and resulting in a decrease in their cost of capital. According to their model, they confirm a green premium ranging from 0.43 to 17.96 basis points.
Gianfrate and Peri (
2019) suggest that green bond issuers enjoy certain advantages over issuers of conventional brown bonds. These green bonds typically have yields that are 14 to 19 basis points lower than conventional bonds. This result suggests that it is acceptable for investors to support corporate green projects and investments by purchasing green bonds with lower yields. In addition,
Wang et al. (
2020) point out that since green bond contracts require issuers to fulfill environmental commitments, firms can mitigate environmental risks and obtain a better environmental reputation by issuing green bonds. Further, corporate green investment can improve environmental performance, reduce environmental risks, and enhance corporate credit status. As a result, green bonds are supposed to have pricing premiums over non-green bonds. They argue that the yields on green bonds are 34 basis points lower than the yields on conventional bonds. The green label has a positive impact, leading to a saving of USD 100.6 million in the cost of capital for companies issuing these bonds. In addition, several studies emphasize the role of green bonds as an effective tool for risk diversification and hedging, especially in times of market stress, which provides reliable market support for the lower cost of capital of green bonds (
Belguith, 2025;
Gazi et al., 2024;
Haq et al., 2021;
Rehan et al., 2024;
Trancoso & Gomes, 2024). However, some other literature does not support this difference.
Flammer (
2021) finds no evidence that issuing green bonds can reduce the cost of capital. In addition,
Tang and Zhang (
2020) also argue that there is no difference between the yields of green bonds and conventional bonds.
As for corporate environmental disclosure, some previous studies categorize corporate environmental disclosure into symbolic and substantive disclosure (
Adu et al., 2023;
Haque & Ntim, 2020). To issue green bonds, firms are generally required to disclose sustainable finance frameworks and publish annual green bond reports detailing the implementation status of green projects, including metrics such as reductions in GHG emissions and energy consumption. Therefore, green bond issuance can be interpreted as a form of composite environmental disclosure, encompassing both symbolic commitments (i.e., self-reported environmental commitments) and substantive components, such as SPTs and KPIs related to GHG emissions and energy consumption. In both cases, both symbolic and substantive environmental disclosures are associated with the improvement in corporate financial performance. Many previous studies indicate that environmental disclosure is positively related to corporate financial performance (
Broadstock et al., 2018;
Clarkson et al., 2013;
Iatridis, 2013;
Plumlee et al., 2015). Such studies generally use the environmental disclosure index to measure corporate symbolic environmental disclosure.
Haque and Ntim (
2020) and
Adu et al. (
2023) measure corporate environmental disclosure by using an environmental disclosure index that is constructed by a series of dummy variables that measure corporate self-reporting of carbon reduction initiatives. They state that only symbolic carbon reduction initiatives enhance corporate financial performance, including ROA and Tobin’s Q, while substantive carbon reductions have no significant impact. Previous research provides some explanations for this positive relationship between environmental disclosure and corporate financial performance. Several studies suggest that environmental disclosure enhances the ability of investors to assess the future opportunities and potential risks of companies, thereby reducing investment uncertainty and ultimately lowering the cost of capital (
Dhaliwal et al., 2011;
Healy & Palepu, 2001). In addition, greater disclosure levels can enhance corporate legitimacy among institutional investors, thus making it easier for companies to obtain low-cost financing and tax incentives (
Ntim, 2016;
Suchman, 1995).
Previous studies have rarely investigated the impact of such composite environmental disclosure of green bonds on corporate financial performance. Therefore, in order to fill this existing research gap and provide new evidence for this research area, this study tests the following hypothesis:
Hypothesis 3. Issuing green bonds improves corporate financial performance.