We do our negotiations today, everything is gonna be open, all the cards are gonna be on the table. There's gonna be no lying, bluffing, because everybody knows everything. And we're gonna do that so as to illustrate the pie. In our first problem, we have Alice and Bob who are trying to divide up something of size 9. The question is how much should Alice get and how much should Bob get? In order to answer that, we first have to say what they would get if they don't reach an agreement. What we'll argue is that Alice will get 1 and Bob will get 2. With that as the background, my question to you is, how much of the nine do you think Alice will get compared compared to Bob? >> Alice gets four. >> Alice gets four and Bob gets five. Any other choices? >> Four and a half. >> Four and a half. >> 3 and 6. >> 3 and 6. Show of hands. How many people go with 3 and 6? How many people go with four and a half, four and a half? And how many people go with four and five? Actually, it's almost a third, a third, a third between that, which is kind of interesting. So it says that we don't necessarily have consensus on what is a fair outcome or what is an expected outcome here. So let's start with this notion of what's the pie in this case. And my view is that we're not really trying to divide up nine, what we really have to divide up is six. In the sense that if they don't reach an agreement, Alice is gonna get 1 and Bob is gonna get 2 and so that three is already taken care of, it's not on the table. The reason we're having this negotiation is to go from 3 to 9 or to get the extra 6. Who is needed more to get that 6, Alice or Bob? >> [INAUDIBLE] >> Alice because she's behind but if Bob says no, what happens to that 6? >> [INAUDIBLE] >> Well no, if Bob says no. >> [INAUDIBLE] >> Then they go to the 1 and 2. So in order to go from the 1 plus 2, all the way up to the 9, who is needed more, Alice or Bob? >> Equal. >> I think they're equally needed because if either party says no, it takes two hands to get a handshake, and so if either party says no, that 6 disappears. Therefore, how should that 6 be divided up, 3 and 3? If we do that, what it means is that Alice gets 4 and Bob gets 5. I think once you see things in the context of the pie, then figuring out how to divide it up isn't so hard. Now what I want you to do is to use that principle as we apply it to more realistic and more interesting problems. So that's it, that's the theory of the pie. It is what people get by working together compared to what they get if they don't reach an agreement. Okay.