The polluter pays principle (PPP) is a basic economic idea that firms or consumers should pay for the cost of the negative externality they create. The polluter pays principle usually refers to environmental costs, but it could be extended to any external cost. Forcing polluters to bear the costs of their activities is alsosaid to enhance economic efficiency.Appropriately applied, policies based on a polluter paysprinciple (PPP) should enable us to protect the environment
without sacrificing the efficiency of a free market economic system