中文摘要：

在混合所有制经济中，厂商的产权结构将影响合作研发的效率及福利结果，并使合作研发后可能形成合谋的反垄断控制标准发生变化。本文使用部分私有化的混合寡头模型对以上问题进行研究．结果显示厂商的研发投入水平与混合所有制厂商中的非国有资本比重正相关，但消费者剩余及社会总福利与非国有资本比重的关系呈倒U型。当混合所有制厂商中的国有产权比重较高时．混合所有制厂商在“市场换技术”的目标下有动力与非国有资本厂商在产品市场中合谋．这种情形下的合谋能够提高社会总福利．并构成了本文所定义的合意合谋；当混合所有制厂商中的国有产权比重较低时，混合所有制厂商同样有动力参与合谋，但此时合谋将对社会总福利造成损害；此外厂商合谋的稳定性在混合所有制下更高。从反垄断控制的角度，以上结果显示，在混合所有制下对厂商合作研发后的合谋应适用合理推定的原则进行判断。

英文摘要：

The firm＇s property structure will impact the efficiency and welfare of R＆D cooperation under mixed ownership economy, and also impact anti-trust control standards of the collusion after R＆D cooperation. This paper uses mixed oligopoly to research these issues, the results show that R＆D investment level of the firm is positively correlated with the proportion of non-state-owned property, but the relationship of consumer surplus and social welfare to the proportion of non-state-owned property is inverted U-shape. When the proportion of stated- owned property is higher, the mixed ownership firm has an incentive to be in collusion with non-state-owned firm, and this kind of collusion will improve the total social welfare. When the proportion of stated-owned property is lower, the mixed ownership firm also has an incentive to be in collusion with non-state-owned firm, but the collusion will harm the total social welfare. In addition, the collusion under mixed ownership economy is higher stability. These results indicate that we should use the rule of reason principle to judge the collusion under mixed ownership economy.