Externalities refer to the beneficial or harmful effects of the production and consumption behaviors of economic agents on the production and consumption behaviors of other economic agents  A positive externality means that the activities of an individual economic agent benefit others or society at no cost to the beneficiaries
Negative externalities refer to the fact that the activities of an individual of economic behavior cause harm to others or society, but the person who causes the negative externality does not bear the cost for it
A factory built a poverty alleviation workshop in the village to facilitate the nearby employment of the villagers