Abstract: How to recognize the behavior of shareholders’ over-appointment of directors and effectively regulate the decision-making mechanism of the board of directors has become an urgent issue in the field of corporate governance. Existing studies have mainly explored the impact of controlling shareholders’ over-appointment of directors on the economic decision-making behavior of enterprises, and there is little literature discussing the perspective of non-controlling shareholders’ over-appointment of directors.In view of this, this paper takes listed family firms in China from 2008 to 2021 as the research object and examines in depth the relationship between over-appointment of directors by non-family shareholders and the quality of corporate accounting information. It is found that over-appointment of boards by non-family shareholders reduces corporate accounting information quality. Mechanism analysis shows that non-family shareholders’ over-appointment of boards of directors exacerbates Type I agency conflicts, which in turn leads to a decrease in the quality of corporate accounting information. Further research finds that the negative effect of over-appointment of directors by non-family shareholders on the quality of corporate accounting information is more significant when the quality of internal control is lower, the firm is in a non-digital transition period, external audit supervision is weaker, and the regional marketization process is slower. The analysis of economic consequences suggests that the over-appointment of directors by non-family shareholders decreases the quality of accounting information, thereby increasing the risk of a firm’s stock price collapse. In other words, the quality of accounting information partially mediates between these two factors.

Key words: family firms, non-family shareholders, over-appointed directors, agent conflict, quality of accounting information