00:01
So here we have a whole bunch of externalities, right? so we have negative externalities in consumption.
00:12
We also have negative externalities in production.
00:20
So both of these negative externalities means that equilibrium q is going to be greater than optimal or actually they use the word efficient here let's use the word efficient greater than efficient cue right and we can see that if we want to sketch a diagram if i sketch a market quantity price let's say demand and supply here's the market allocation right if we have a negative externality in consumption that means demand comes down if we've got a negative externality in output in production, that means supply goes up.
01:02
Both of these cases, right, the q efficient is lower than the q market, right? so when bad things are happening, the market produces too much, right? the equilibrium quantity is larger than an efficient.
01:17
There's too much quantity.
01:19
For the next part, you can see where we're going, right? when you have a positive externality in consumption, or in output, what's going to happen is that the equilibrium quantity is going to be smaller than the efficient quantity.
01:40
So before we had when something bad was happening, the market produced too much...