PPCs for increasing, decreasing and constant opportunity cost

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PPCs for increasing, decreasing and constant opportunity cost발음듣기

[Instructor] So we have three different possible production possibility curves for rabbits and berries here, which we've already talked about in other videos.발음듣기

But the reason why I'm showing you three different curves is because these three different curves clearly have different shapes.발음듣기

And we wanna think about why you would have and under what scenarios would you have these different shapes?발음듣기

Here, our production possibility curve, or our PPC it looks like a straight line.발음듣기

Here, it looks like it's bowed out from the origin it looks like it's popping out in that direction.발음듣기

And here, it looks like it's bowed in to the origin it's popping in in this direction.발음듣기

So the first thing I'm going to do is ask you a question.발음듣기

Which one describes the scenario where for every extra rabbit I catch, every incremental rabbit I'm giving up more and more in terms of berries?발음듣기

Or another way of thinking about it is as I catch more and more rabbits, the opportunity cost in terms of berries is increasing.발음듣기

Which one of these curves describes that?발음듣기

Well some of you might have already seen the video on Khan Academy, on increasing opportunity cost and you might recognize that this curve here.발음듣기

But let's just review it, so there's a world where I'm eating all berries.발음듣기

And I can get, I can pick 300 berries a day, but maybe I decide to go after that first rabbit that just likes to hang out and play with my knives.발음듣기

And so when I catch that it's very easy to catch, so I don't give up a lot in terms of berries, especially because I'm probably not the berries I'm giving up are probably the ones that are hardest to pick.발음듣기

And so let's say that first rabbit, the opportunity cost I pick 20 less berries, so notice, when I increase the rabbits by one, my berries go down by 20,발음듣기

so my opportunity cost is 20 berries for that first rabbit.발음듣기

But let's say that second rabbit is a little bit harder to catch, and I'm not giving up the quite so hard to pick berries and so when I pick that next, or when I hunt that next rabbit, I should say, then I've given up 40 berries.발음듣기

So notice, my opportunity cost has increased.발음듣기

For that first rabbit, my opportunity cost was 20 berries.발음듣기

For that second rabbit, my opportunity cost is 40 berries.발음듣기

And it keeps going, then third rabbit I'm going to give up 60 berries.발음듣기

That fourth rabbit, I'm gonna give up 80 berries,발음듣기

80 berries, and then last but not least that fifth rabbit, which is the most that I can hunt in a day, I'm gonna give up 100 berries 'cuz here, I'm going after the really nimble rabbit the really sly rabbit.발음듣기

And I'm giving up literally the low-hanging fruit in terms of berries the one, they might be on the ground just ready for me to pick up.발음듣기

And so the important realization from this video is this bowed out shape right over here this is describing an increasing opportunity cost.발음듣기

Let me write that down, increasing increasing, O.C. for opportunity cost.발음듣기

So with that out of the way, which of these would describe a decreasing opportunity cost?발음듣기

Maybe you could imagine a scenario where every incremental rabbit I catch I get better and better at catching rabbits.발음듣기

Well you might guess that, well look if this one is increasing and I'm bowed out then being bowed in would be a decreasing opportunity cost.발음듣기

Decreasing opportunity cost, and let's make sure that it makes sense, so we could go back to the scenario where we're doing nothing but picking berries.발음듣기

And let's say that first rabbit, so we're gonna talk about a different scenario now, that first rabbit I had to train myself to be able to get rabbits I have to buy the tools, I have to stretch it takes me a lot of effort to get that first rabbit.발음듣기

And so, there, I give up 100 berries, so my opportunity cost for that first rabbit was 100 berries.발음듣기

But then for that second rabbit my opportunity cost is 80 berries.발음듣기

Maybe now, I've kind of gotten the hang of it.발음듣기

I've already bought my rabbit catching shoes.발음듣기

I've already invested in that.발음듣기

I'm all stretched and limber, maybe those rabbits like to hang out together, and so that keeps on going.발음듣기

So that third rabbit, my opportunity cost is 60 berries.발음듣기

I'm getting really good at catching rabbits so clearly, you see here, that for each incremental rabbit I get, my opportunity cost is decreasing all the way to that fifth rabbit maybe my opportunity cost is 20 berries.발음듣기

To catch that next extra rabbit I'm giving up those 20 berries.발음듣기

So very clearly, you see a decreasing opportunity cost.발음듣기

And so, by deductive reasoning, you might be able to say,발음듣기

Well, okay, this straight line must represent a constant opportunity cost.발음듣기

And that is, indeed, what it shows.발음듣기

For every rabbit, every rabbit you catch you're giving up exactly, you're giving up exactly 60 berries, every time I catch a rabbit I give up 60 berries, so my opportunity cost for rabbits, in terms of berries, is just a constant 60.발음듣기

And so this is a scenario, if you were imagining in this fictional world we created, where every rabbit is about as easy to catch as any other one.발음듣기

And every berry is about as easy to pick or find as any other one, and so, the trade off the amount of time I spent for each incremental rabbit I'm giving up a fixed amount of berries.발음듣기

No matter how many rabbits I go for and no matter how many berries I am currently at so that's a constant opportunity cost when you have a straight line.발음듣기

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