Answer:
Benefit is less
Step-by-step explanation:
An externality is when the activities of an economic agent has either costs or benefits on third party economic agent or the society as a whole.
Externality can either be negative or positive.
Negative externality is when the cost is greater than the benefits to third party economic agent or the society as a whole. E.g. pollution
Positive externality is when the benefit is greater than the cost to third party economic agent or the society as a whole. E.g. research