Final answer:
The marginal external cost of generating a kilowatt of electricity, given the marginal social cost of $0.10 and the marginal private cost of $0.08, is $0.02.
Step-by-step explanation:
If the marginal social cost of generating a kilowatt of electricity is $0.10, and the marginal private cost is $0.08, the marginal external cost is the difference between these two costs. To find the marginal external cost, we subtract the marginal private cost from the marginal social cost.
Marginal external cost = Marginal social cost − Marginal private cost
= $0.10 − $0.08
= $0.02 per kilowatt
So, the marginal external cost of generating a kilowatt of electricity is $0.02. This is the additional cost imposed on society that is not accounted for by the private producer of the electricity.