Cooperative green innovation.

Cooperative green innovation is an important tool to cope with global climate change and this article highlights cooperative green innovation with game theory. Some interesting conclusions are achieved. First, emission tax stimulates the innovation for all firms. Second, free-rider phenomena appear in cooperative green innovation. When the cooperative green innovation requires big investment, firms have intention to launch free-rider. Finally, the underinvestment of cooperative green innovation exists. This article suggests to regulate innovative investment and to subsidize to improve cooperative green innovation.