Marginal cost represents the change in total cost that arises when the quantity produced is changed by one unit. In short, it is the cost of one additional unit of a good. The marginal cost may vary with volume or with each level of production.
Perspectives are different frameworks from which to explore the knowledge around sustainable sanitation and water management. Perspectives are like filters: they compile and structure the information that relate to a given focus theme, region or context. This allows you to quickly navigate to the content of your particular interest while promoting the holistic understanding of sustainable sanitation and water management.