A negative externality (likewise called "outside cost" or "outer diseconomy") is a monetary action that forces an adverse consequence on an inconsequential outsider. It can emerge either during the creation or the utilization of a decent or service. [19] Pollution is named an externality since it forces costs on individuals who are "outer" to the maker and customer of the dirtying product. [20] Barry Commoner remarked on the expenses of externalities