EXTERNALITIES occur when the actions of consumers and producers give rise to SIDE-EFFECTS that impact THIRD PARTIES who are not part of these activities.
…if the impact on third parties involves BENEFITS, then it is referred to as a POSITIVE EXTERNALITY, also known as an EXTERNAL BENEFIT.
…if the impact on third parties involves COSTS, then it is referred to as a NEGATIVE EXTERNALITY, also known as an EXTERNAL COST.
…if the benefit arises from PRODUCTION activities it is referred to as a ‘POSITIVE EXTERNALITY OF PRODUCTION’
…if this cost arises from PRODUCTION activities it is referred to as a ‘NEGATIVE EXTERNALITY OF PRODUCTION’
…if the benefit arises from CONSUMPTION activities it is referred to as a ‘POSITIVE EXTERNALITY OF CONSUMPTION’
…if this cost arises from CONSUMPTION activities it is referred to as a ‘NEGATIVE EXTERNALITY OF CONSUMPTION’
GOODS/SERVICES that create EXTERNAL BENEFITS are called MERIT GOODS.
GOODS/SERVICES that create EXTERNAL COSTS are called DEMERIT GOODS.