Explain the two causes of market failures. Given their definitions, could a market be affected by both types of market failures simultaneously?

Explain the two causes of market failures. Given their definitions, could a market be affected by both types of market failures simultaneously? What divergences arise between equilibrium output and efficient output when (a) negative externalities and (b) positive externalities are present? How might government correct these divergences? Cite an example (other than the text examples) of an external cost and an external benefit.