非效率投資—為管理層過度擴張所致之過度投資與受限於融資障礙之投資不足的總稱，學者們一致認為非效率投資對企業長期價值有害。若能了解如何透過提升資訊透明度與可信度來改善資源配置，可以幫助公司未來在制定決策時，有效克服代理問題與融資約束，以減少非效率投資發生的情況。本研究係探討永續揭露品質對投資效率之影響，並檢析外部確信以及確信提供者之調節作用。本研究以 2019 年至 2024 年為研究期間，使用臺灣經濟新報（TEJ）的上市上櫃電子業公司為研究對象，實證結果發現，提升永續揭露品質之公司，可以顯著抑制過度投資及改善投資不足之情況；於揭露中加入外部確信之公司，能顯著強化揭露品質並緩解投資不足發生之情形；然而，由四大會計師事務所提供確信，則無法對抑制過度投資或緩解投資不足產生更顯著之調節差異。;In recent years， sustainability disclosure has increasingly gained attention in capitalmarkets; however， in practice， disclosures lacking credibility are often susceptible togreenwashing. Inefficient investment—an umbrella term encompassing over-investment driven by managerial over-expansion and under-investment constrained byfinancing obstacles—is widely recognized by scholars as detrimental to a firm′s long-term value. Understanding how to improve resource allocation by enhancinginformation transparency and credibility can assist firms in effectively overcomingagency problems and financing constraints during decision-making， thereby reducingthe incidence of inefficient investment. This study investigates the impact ofsustainability disclosure quality on investment efficiency and examines the moderatingroles of external assurance and assurance providers. Based on a sample of listed andOTC electronics companies in Taiwan from the Taiwan Economic Journal (TEJ)database for the period 2019 to 2024， the empirical results reveal that improvingsustainability disclosure quality can significantly curb the occurrence of over-investment and under-investment. Furthermore， obtaining external assurancesignificantly strengthens the effect of disclosure quality in mitigating under-investment.However， the use of Big 4 accounting firms as assurance providers does not exhibit asignificantly different moderating effect on either curbing over-investment ormitigating under-investment.
