If private contracting is impossible, too many cigars would be produced and consumed. The market price of cigars is too low.
Negative externality is when the production or consumption activities of economic agents negatively affects third parties not involved in production or consumption.
For example, smoking a cigar affects others that are not smoking that are around the person that is smoking. Negative externality occurs because the cost of production or consumption is too low.
To learn more about externalities, please check: https://brainly.com/question/26266710