There are a number of types of externality. Some are of particular relevance to the copper industry. The above suggest that these externalities are always negative and result in external costs. In addition to negative externalities there are positive externalities i.e. benefits accruing to non-participants in the market place arising from the consumption and production of goods and services. These are the external benefits.
Economists are always interested in the use of resources.
When externalities result in third parties having to use resources in response to the external costs and benefits, such as those residents of Copperbelt who need hospital care or have to take days off work due to pollution related illness, there has been a misallocation of resources. They recognise that the market for the good has not taken into account all of the costs and benefits from production and consumption. This is called market failure. Supply and demand analysis can be used to consider the effect of such negative externalities. Price can be considered to be a measure of the benefit that a consumer derives from the consumption of a unit of a good or service.