它认为市场结构决定了企业行为，比如企业的经营情况和利润。而企业的这些行为又进一步决定了市场的竞争状况，并且可以用一些市场结构指数变现出来，比如市场份额和集中度。
It believes that market structure determines the behavior of enterprises in the market, and then the competition condition which is determined by the preference and revenue of the firms could be described by some market structure indexes, like market share and concentration ratio .

[1]It believes that market structure determines the behavior of enterprises in the market, [2]. And then the competition condition which is determined by the [3]preference and revenue of the firms could be described by some market structure indexes, like market share and concentration ratio .

[1] It believes... It指什么？某个人/物，还是形式主语，如果是物，“物：怎么能”认为“呢？
我认为it这里做形式主语好一些，可以改成：It is believed...据认为...,据信....

[2]处是不是漏掉了"比如企业的经营情况和利润".我认为是需要的：such as level of enterprise management and profit.

[3] 是performance?

除了上面3个，还做了一些改动，不是管理专业的，有不当之处，仅供参考！
It is believed that market structure determines the behavior of enterprises in the market, such as level of enterprise management and the profit. And furthermore, the market competition condition which is determined by these behaviors could be described by certain market structure indexes, like market share and concentration ratio