An excessive number of flights in the airline industry creates avoidable harm to the environment. Which policy is most likely to lead to the socially optimum number of flights?
- Aa complete ban on flights removing all private and external costs
- Bgreater deregulation of the global airline industry
- Cpublishing information to highlight the negative effects of flying on the environment
- Dthe payment of a subsidy per passenger equal to the difference between the private and social benefit