Chapter 5- EXternalities Public economics
1 Chapter 5 - Externalities Public Economics
Externality Defined An externality is present when the activity of one entity(person or firm) directly affects the welfare of another entity in a way that is outside the market mechanism Negative externality: These activities impose damages on others Positive externality: These activities benefits on others
2 Externality Defined • An externality is present when the activity of one entity (person or firm) directly affects the welfare of another entity in a way that is outside the market mechanism. – Negative externality: These activities impose damages on others. – Positive externality: These activities benefits on others
Examples of Externalities Negative Externalities Positive externalities Pollution Research development Cell phones in a movie theater Vaccinations Congestion on the internet A neighbor's nice landscape Drinking and driving Students asking good questions Student cheating that changes in class the grade curve The"LoJack" anti-theft devise The Clubanti-theft devise for for automobiles automobiles Not Considered Externalities Land prices rising in urban area Known as"pecuniary externalities
3 Examples of Externalities • Negative Externalities – Pollution – Cell phones in a movie theater – Congestion on the internet – Drinking and driving – Student cheating that changes the grade curve – The “Club” anti-theft devise for automobiles. • Positive Externalities – Research & development – Vaccinations – A neighbor’s nice landscape – Students asking good questions in class – The “LoJack” anti-theft devise for automobiles • Not Considered Externalities – Land prices rising in urban area. – Known as “pecuniary” externalities
Nature of externalities Arise because there is no market price attached to the activity Can be produced by people or firms Can be positive or negative Public goods are special case Positive externality's full effects are felt by everyone in the economy
4 Nature of Externalities • Arise because there is no market price attached to the activity. • Can be produced by people or firms. • Can be positive or negative. • Public goods are special case. – Positive externality’s full effects are felt by everyone in the economy
Graphical Analysis: Negative Externalities For simplicity, assume that a steel firm dumps pollution into a river that harms a fishery downstream Competitive markets, firms maximize profits Note that steel firm only care's about its own profits not the fishery Fishery only cares about its profits, not the steel firms
5 Graphical Analysis: Negative Externalities • For simplicity, assume that a steel firm dumps pollution into a river that harms a fishery downstream. • Competitive markets, firms maximize profits – Note that steel firm only care’s about its own profits, not the fishery’s – Fishery only cares about its profits, not the steel firm’s