This graph represents a negative externality situation. Given this, which of the two
curves, X or Y, represents marginal social costs and why?
a. Curve X, because if there is a negative externality, external costs are associated with
it: social costs = external costs + private costs, therefore the marginal social cost curve
must lie above the marginal private cost curve.
b. Curve Y, because if there is a negative externality, negative external costs are
associated with it: social costs = negative external costs + private costs, therefore the
marginal social cost curve must lie below the marginal private cost curve.
c. Curve X, because if there is a negative externality, external benefits are associated
with it: social costs = external benefits + private costs, therefore the marginal social cost
curve must lie above the marginal private cost curve.
d. Curve Y, because if there is a negative externality, negative external benefits are
associated with it: social costs = negative external benefits + private costs, therefore the
marginal social cost curve must lie below the marginal private cost curve.
Damian is texting while driving and ends up slamming into the back end of the car in
front of him, which then strikes the car in front of it. By texting while driving, Damian
has created a
a. negative externality.
b. positive externality.