Explain the impact of external costs and external benefi ts on resource allocation. Why are public goods not produced in suffi cient quantities by private markets? Which of the following are public...

Explain the impact of external costs and external benefi ts on resource allocation. Why are public goods not produced in suffi cient quantities by private markets? Which of the following are public goods? a. Air bags b. Pencils c. Cycle helmets d. City streetlights e. Contact lenses