This paper explores the pricing of green bonds in the Italian primary and secondary market and their implications for sustainability by investigating the effect that a green label has on a bond's spread through propensity score matching. From a sample of 420 fixed-rate, euro-denominated bonds priced at on the euro mid-swap from 2014 to the first half of 2021, bonds with a green label are matched with conventional bonds, to assess whether there is a significant difference in spreads between them. The results on the primary market show that green bonds' issuance spread is, on average, 35 to 40 basis points lower than that of comparable conventional bonds at a highly significance level.

The spread discount seems to persist regardless of the issuer's sector, even with a difference in the magnitude, being remarkably higher for corporates. On the secondary market, the estimation results confirm the discount impact of the green label on the bonds' market spread, even if this impact is lower than at the issuance. This study aims at giving better coverage of the advantages green bonds are able to generate also in a relatively small and illiquid financial markets. Furthermore, we show that green bonds are effective instruments for issuers to achieve a lower cost of debt to finance green projects and for investors to support the transition to a greener and more sustainable economy.

本文通过调查绿色标签通过倾向得分匹配对债券利差的影响，探讨了意大利一级和二级市场绿色债券的定价及其对可持续性的影响。从 2014 年至 2021 年上半年以欧元互换中间价定价的 420 只固定利率、欧元计价债券样本中，将绿色标签债券与常规债券进行匹配，以评估两者之间是否存在显着差异。在他们之间传播。一级市场的结果显示，绿色债券的发行利差平均比可比传统债券低35至40个基点，具有高度显着性。

无论发行人所在的行业如何，利差折扣似乎都持续存在，即使幅度不同，对于企业而言，这种折扣要高得多。在二级市场上，估计结果证实了绿色标签对债券市场价差的贴现影响，即使这种影响低于发行时的影响。本研究旨在更好地涵盖绿色债券在相对较小且流动性不足的金融市场中也能够产生的优势。此外，我们表明，绿色债券是发行人降低债务成本为绿色项目融资的有效工具，也是投资者支持向更绿色和更可持续经济转型的有效工具。