Can Lenders Identify Heterogeneity in the Voluntary Assurance of Sustainability Reports? International Evidence
研究了贷款人能否区分企业可持续发展报告自愿保证的异质性，发现只有可持续发展绩效高于行业平均水平的企业才能通过保证降低债务融资成本，而绩效差的企业则无此好处，贷款人有效惩罚了绿色洗白行为。
This paper examines whether lenders are capable of discerning heterogeneity in the voluntary assurance of sustainability reports and how this capability influences corporate debt financing costs. Leveraging an international dataset between 2010 and 2019, we find that assurance only reduces debt financing costs for firms that exhibit above‐industry‐average sustainability performance, whereas firms with weak sustainability performance gain no such benefit. Lenders effectively penalize greenwashing by discounting cosmetic assurance but reward substantive verification for genuinely sustainable firms. This assurance premium is particularly strong amid high levels of ESG (environmental, social, and governance) rating disagreement, when third‐party data is unreliable. Moreover, lenders incorporate a valuation premium for high‐quality assurance engagements, particularly when the services are provided by accounting firms (particularly Big 4 firms), cover a broader scope, or involve deeper process rigour or more comprehensive statements. Further analyses demonstrate that the heterogeneity in the debt financing cost reduction effect of assurance, conditional on sustainability performance, tends not to be immediate but gradual. Over time, lenders learn to distinguish between credible assurance and symbolic efforts, adjusting pricing accordingly. Our study highlights the nuanced role of assurance in debt markets and underscores the importance of performance‐aligned sustainability disclosure.