You had to choose grades, so you had to choose Alpha and Beta, and this table told us what outcome would arise.

大家通过选择α和β来确定各自的成绩,这个表格列出了可能的结果

耶鲁公开课 - 博弈论课程节选

It's still I'm choosing Alpha and Beta, my pair is choosing Alpha and Beta, and the grades are the same as they were before.

还是我选α和β,我对手选α和β,成绩的评判和之前是一模一样的

耶鲁公开课 - 博弈论课程节选

We'll come back to this, but beta of the stock is a measure of how much it moves with the market and the alpha of a stock is how much it outperforms the market.

回到原先的话题,beta用以衡量,本公司跟随市场变化的程度,alpha衡量超过市场的表现

耶鲁公开课 - 金融市场课程节选

All right, so here once again is our same matrix with me and my pair, choosing actions Alpha and Beta, but this time I'm going to put numbers in here.

我们首先讨论我和我对手,选择α或β的矩阵,不过这次我们用数字来表述

耶鲁公开课 - 博弈论课程节选

What I'm gonna do is draw a larger table, the same basic structure: I'm choosing Alpha and Beta on the rows, my pair is choosing Alpha and Beta on the columns, but now I'm going to put both grades in.

我要画个结构相同的大表格,用列来表示我选α还是β,用行来表示我对手选α还是β,但我要把两人成绩写在一个单元格里

耶鲁公开课 - 博弈论课程节选

So what I'm going to do is I'm going to put me here, and my pair, the person I'm randomly paired with here, and Alpha and Beta, which are the choices I'm going to make here and on the columns Alpha and Beta, the choices my pair is making.

那么我把我写在这里,我对手,就是被随机分到的人写在这,还有是α和β,就是我要做的选择,还有我对手要做的选择

耶鲁公开课 - 博弈论课程节选

So Alpha in this case is better against Alpha, and Beta is better against Beta, but neither dominates each other.

所以对方选α时我应该也选α,她选β我也应该选β,这里没有优势策略

耶鲁公开课 - 博弈论课程节选

If I choose Alpha and she chooses Alpha to get 0; Beta she gets -1. Alpha is better.

如果我选α,她选α她得0,选β她得-1,选α更好

耶鲁公开课 - 博弈论课程节选

If the pair chooses Alpha and she chose Beta, she gets -1.

对手选α她选β,她得到-1

耶鲁公开课 - 博弈论课程节选

And once I know that she's going to choose Alpha, it's clear that I should choose Alpha and get 0 rather than Beta and get -3. So I should choose Alpha also.

一旦我意识到她会选α的时候,很显然我应该也选α来得到0单位效用,而不是选β只得到-3,所以我也选α

耶鲁公开课 - 博弈论课程节选

I mean if you chose Alpha, you're swinging from A to B-; and from Beta, swinging from B+ to C.

要是你选α,你的分数会在A到B-,选β,分数范围会在B+到C

耶鲁公开课 - 博弈论课程节选

But if I choose Alpha and my pair chooses Beta, I get an A and she gets a C.

要是我选α我对手选β,我得A 她得C

耶鲁公开课 - 博弈论课程节选

If you put Beta and you're paired with Alpha, you'll get a C and your pair an A.

如果你选β你对手选α,你得C你对手得A

耶鲁公开课 - 博弈论课程节选

And if I choose Beta and she chooses Alpha, then it's me who gets the C and it's her who gets the A.

如果我选β她选α,我得C而她得A

耶鲁公开课 - 博弈论课程节选

Well they won't be, If you put Alpha and you're paired with Beta, then you will get an A and your pair a C.

纯属娱乐,大家别当真,如果你选α而你对手选β,那么你得A你对手得C

耶鲁公开课 - 博弈论课程节选

And if I put Beta and she puts Alpha, then she gets an A.

如果我选β她选α 那么她得A

耶鲁公开课 - 博弈论课程节选

If I put Alpha and she put a Beta, I got an A, and if I put Beta and she put an Alpha, I got a C.

如果我选α她选β 我得A,如果我选β她选α 那么我得C

耶鲁公开课 - 博弈论课程节选

If my opponent chooses Beta and I choose Alpha, I get 3; Beta, I get 1. Once again Alpha is better.

如果我对手选β,我选α我得3,选β我得1,也是选α好

耶鲁公开课 - 博弈论课程节选

If my opponent chooses Alpha and I choose Alpha, I get 0; Beta, I get -1. So Alpha would be better.

如果我对手选α我选α,我得0,选β我得-1,选α更好

耶鲁公开课 - 博弈论课程节选

If the pair chooses Beta, then if she chooses Alpha she gets 3, Beta she gets 1, and 3 is bigger than 1.

如果她对手选β,她选α得到3,她选β得到1,3也比1大

耶鲁公开课 - 博弈论课程节选

Alpha was dominant before--it dominated Beta before-- and it still dominates Beta. Let's just check.

是优势策略,β是劣势策略,在这里α依然优于β,我们来验证下

耶鲁公开课 - 博弈论课程节选

So I could communicate with Alice on agreements, but back home I'm going to go ahead and choose Alpha anyway; all the better if she's choosing Beta.

所以我可以和爱丽丝说好了,但回家之后我还是可以选α的,要是她还选β那就更好了

耶鲁公开课 - 博弈论课程节选

Now, it turns out that this game, this Prisoner's Dilemma, with the Alpha's and Beta's, or essentially the same game, has been played many, many, many times in experiments.

实际上,囚徒困境这个博弈,比如选择α和β,或者类似的博弈,在现实中进行过很多次实验

耶鲁公开课 - 博弈论课程节选

So 236--I'm sorry 238--chose Alpha, and 36 chose Beta.

38人选α 36人选β

耶鲁公开课 - 博弈论课程节选

If I put Alpha and my pair puts Beta, then she gets a C.

如果我选α我对手选β,那么她得C

耶鲁公开课 - 博弈论课程节选

So, for example, if you had chosen Beta and your pair had chosen Alpha, then you would get a C and your pair would get an A.

比如说你选了β而你的对手选了α,你会得到C而你的对手会得到A

耶鲁公开课 - 博弈论课程节选

Conversely, if I chose a Beta and my pair chooses an Alpha, so I end up with a C and she ends up with an A, then you know I have a bad time explaining to my parents why I got a C in this class, and I have to say about how I'm going to be president anyway.

相反如果我选β我对手选α,我得到C她得到了A,我回家后很难跟父母,解释为什么我只得到了C,然后我还得表示下雄心壮志

耶鲁公开课 - 博弈论课程节选