an external cost or external benefit is also known as
Externality Two British economists are credited with having initiated the formal study of externalities, or "spillover effects": Henry Sidgwick (1838–1900) is credited with first articulating, and Arthur C. Pigou (1877–1959) is credited with formalizing the concept of externalities.[5]
Cost of goods sold Costs are associated with particular goods using one of the several formulas, including specific identification, first-in first-out (FIFO), or average cost. Costs include all costs of purchase, costs of conversion and other costs that are incurred in bringing the inventories to their present location and condition. Costs of goods made by the businesses include material, labor, and allocated overhead. The costs of those goods which are not yet sold are deferred as costs of inventory until the inventory is sold or written down in value.