This paper identifies the optimal pollution level under the assumptions of linear, quadratic and exponential damage and abatement cost functions and investigates analytically the certain restrictions that the existence of this optimal level requires. The evaluation of the benefit area is discussed and the mathematical formulation provides the appropriate methods, so that to be calculated. The positive, at least from a theoretical point of view, is that both the quadratic and the exponential case obey to the same form of evaluating the benefit area.
