Baghlan City of Afghanistan for manager: an individual within the firm who is responsible for directing the production or sale of the firm’s output. marginal analysis: an examination of how benefits and costs change as the result of changes in certain variables. For example, when a market moves from one equilibrium to another, marginal analysis may be used to explain the direction and magnitude of that change. marginal cost: the change in total economic cost associated with producing an additional unit of some good or service. For a firm, the marginal cost of producing additional output is calculated as the change in total cost divided by the respective change in output. marginal product: the change in output possible from hiring an additional factor of production. For a firm, the marginal product associated with hiring additional units of a factor is calculated as the change in output divided by the respective change in the amount of factor hired. Baghlan City of Afghanistan 2016.