00:01
So we're asked about a good that generates externalities.
00:03
So let's draw a market featuring a good that generates externalities, right? we have a demand curve, which reflects the private marginal benefit of consumption.
00:13
We're going to have a supply curve, which represents the marginal cost of production.
00:18
And now we're going to have a, say, a social marginal benefit curve reflecting the externality, right? this difference reflects the positive externality.
00:30
Benefits to society from the consumption of this good are greater than the benefits to the individual from the consumption of this good.
00:38
That's what the difference between those two lines is just suggesting.
00:43
So the private market equates private benefits and private costs, right? the market quantity is marginal cost equals to marginal benefit, but society would prefer the point where social marginal benefit is equal to marginal cost.
01:02
That is all the benefits, not just the private benefits are at equal to marginal cost.
01:08
So in general, markets will underprivile...