中文摘要：

本文通过超越对数成本函数构建了保险产出的边际成本模型，然后利用古诺一纳什均衡分析了边际成本与市场份额的关系，并通过中国的非平衡面板数据对相关理论关系进行了验证。结果发现：外资公司的边际成本均高于中资公司，寿险公司的边际成本普遍高于产险公司；对于中小型保险公司，边际成本与市场份额显著负相关，而大型保险公司的边际成本与市场份额的相关关系并不显著；产业竞争程度指标显示，与寿险业相比，产险业的竞争程度更为激烈。

英文摘要：

In this paper, we used translog cost function to construct the marginal cost model of the insurance industry, and then Cournot-Nash equilibrium to analyse the relationship between marginal cost and market share. Finally, we used China＇ s unbalanced panel data to test the related theoretical relationship. The results showed that： （ 1 ） the marginal cost of foreign companies are higher than domestic companies, while the marginal cost of life in- surance companies are higher than property and casualty insurance companies; （2） for small and medium sized insurance companies, marginal cost and market share are inversely correlated, while in large insurance companies, there is no definite relationship between the two ; （3） compared with life insurance companies, competition in property and casualty insurance industry is more intense.