If Risk management planning and identification is effective, are there more chances for a project to be successful with mediating effect of stakeholers' intentions towards risk management activities?
Effective the risk management more the project successful yes there is a positive relationship but if stakeholders' are intended towards risk management activities especially implement those risk responses with a sound risk policy, what you think the outcome would be? Saving Changes...
Risk identification and analysis is of limited value if you can't get stakeholders to respond in a timely manner to the risk responses they own.
This is why I always quote Dr. Hillson's definition of risk being uncertainty which matters - if it doesn't matter to your stakeholders then they aren't going to act on recommended responses.