Abstract: Based on the assumption of “economic man's rationality”, the principalagent theory in the new institutional economics has designed a precise, exquisite and delicate principalagent system, which effectively resolves the conflict of interest between the principal and the agent in modern enterprises and improves the operation efficiency of the enterprises. However, the practice of modern enterprises has proved that even though the principalagent system is very precise, exquisite and delicate, it still has not completely solved the conflict of interest between the principal and the agent and the further improvement of the efficiency of enterprise operation. Therefore, it is necessary to expand the theoretical perspective from the hypothesis of “economic man rationality” to “economic man + social man + family man composite rationality”, so as to realize the expansion of the theoretical perspective of principalagent theory. Using the new institutional economics research method and the bilateral symmetric trust mathematical model, this paper proves that: based on the principalagent system, further strengthening the bilateral symmetric trust between principals and agents can further resolve their conflicts of interest and improve the efficiency of enterprise operation. Based on this conclusion, the specific path of strengthening bilateral symmetric trust between principal and agent is optimizing the social trust environment system.

Key words: principalagent theory, institutional basis, bilateral symmetrical trust, efficiency improvement

摘要： 新制度经济学中的委托代理理论基于“经济人理性”假定，设计出了精密、精巧、精致的委托代理制度，有效化解了现代企业中委托人与代理人之间利益冲突并提升了企业运营效率。然而，现代企业实践已经证明，即使委托代理制度十分精密、精巧、精致，仍然没有彻底解决委托人与代理人之间的利益冲突和企业运营效率进一步提升问题。因此，必须拓展既有理论视野，从“经济人理性”假定拓展到“经济人+社会人+家庭人复合理性”假定，这样就能够实现委托代理理论视野的拓展。运用新制度经济学研究方法和双边对称信任数理模型表明：基于委托代理制度，进一步强化委托人与代理人之间双边对称信任度，可以进一步化解他们之间的利益冲突并且改善企业运营效率。基于这一结论，强化委托人与代理人之间双边对称信任度的具体路径是优化社会信任环境系统。

关键词: 委托代理理论, 制度基础, 双边对称信任, 效率改善