Cooperation among rating organizations or among rating organizations and insurers in rate making or in other matters within the scope of this chapter is authorized. The Commissioner may review the cooperative activities and practices and, if after a hearing he finds that the activity or practice is unfair or unreasonable or otherwise inconsistent with this chapter, he may issue a written order specifying in what respects the activity or practice is unfair or unreasonable or otherwise inconsistent with this chapter and requiring the discontinuance of the activity or practice.