本文旨在探討異常勞動力投資與信用評等間之關係。當企業發生異常的勞動力投資時，代表其勞動力投資超過或低於正常營運活動下應有的投資水平。異常的勞動力投資又可分為聘僱不足及過度聘僱。當企業發生聘僱不足時，將因為產能受限而影響盈餘增長空間，並且將削弱產生現金流量的能力；過度聘僱則讓企業產生過高的薪資成本，導致企業盈餘出現下行風險，同時企業將因為超額的薪資成本使現金流量大幅減少。因此本文預期異常勞動力投資程度愈高，信用評等愈差。實證結果顯示，當企業異常勞動力投資增加時，且不論是聘僱不足抑或是過度聘度增加，信評機構都將下修其信用評等。本研究亦發現，在高度競爭的產業中，企業異常勞動力投資增加將使得其信用評等下降。然而低競爭產業之企業則不會有此影響效果。若以企業違約風險分類，於投資層級之企業而言，聘僱不足及過度聘僱皆會影響其信用評等變化。然而投機層級之企業僅會因為過度聘僱增加而使其信用評等降低，聘僱不足增加則不會影響其信用評等變化。

This study aims to investigate the relationship between abnormal labor investment and credit ratings. Abnormal labor investment occurs when a company's labor investment exceeds or falls below the normal level expected in regular business operations. This paper finds that when companies experience an increase in abnormal labor investment, whether it is due to underemployment or overemployment, credit rating agencies downgrade their credit ratings. The study also finds that in highly competitive industries, an increase in abnormal labor investment leads to a decrease in credit ratings. However, this effect is not observed in industries with low competition industry. When categorizing companies based on default risk, it is observed that for investment-grade companies, both underemployment and overemployment affect their credit rating changes. However, for speculative-grade companies, only an increase in overemployment leads to a credit rating downgrade, while underemployment does not affect their credit rating changes.

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