This is a Chinese version of Competitive Strategy. You can find the original course in English from our course catalog. 此版本是Coursera首次尝试推出的中文翻译版。课程视频为英文原版附中文字幕，课程页面和测验已译成中文，帮助中心提供中文支持。 在本课程（共六个模块）中，你将了解企业在战略决策相互依存的情况下如何行事。例如，你的行动会如何影响竞争对手的利润，反之亦然。我们将会借助博弈论的基本工具分析企业如何选择策略以获得竞争优势。
博弈设定 Game Setting
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来自 Ludwig-Maximilians-Universität München (LMU) 的课程
竞争策略（中文版）
420 个评分
从本节课中
关注你的竞争对手 Take Care of Your Competitors
在本模块中，我们将介绍博弈论的基本概念，并分析策略博弈中的竞争情况。我们将明确什么是策略并寻求不同的方式来确定最佳策略或优势策略。我们还将讨论纳什均衡和囚徒困境概念，分析为什么在决策时考量其他局中人的行动至关重要。最后，我们还将分析同时博弈（所有人同时行动）更改为序贯博弈（局中人按序行动）时会出现的情况。
与讲师见面
Tobias KretschmerProfessor
Institute for Strategy, Technology and Organization
So, welcome back. As we're all familiar with simultaneous
games by now, in the next couple of videos, we'll
discuss sequential games or dynamic games as we often call them.
Sequential games are simply put games with some sort of a time aspect in them.
So, one firm acts before the other. It's going to have quite important
implications for playing the game. So, the second firm will be able to play
the game knowing what the first firm has done.
And it's going to be able to adjust its actions accordingly.
And the first firm, on the other hand, has to make a decision without the
requisition knowledge of the follower, right?
I don't know what the second player is going to do.
However, the first firm will keep in mind, that there will be a follower and
this follower is going to react in some sort, rationally.
Okay, so they are going to build up expectations about the reactions of the
follower in my own decisions. Now, I want to illustrate this with an
example related to the movie ET, the Extra Terrestrial.
So, I don't know how much you are a kid of the 70s, but if you are, then you will
remember this scene very, very vividly. Okay?
So, ET has just landed. He's hiding somewhere.
He's terrified. He's hiding in the woods somewhere.
And there are a couple of kids, two kids that see that something is out there in
the woods. It's fairly close to their house, so they
feel, well, you know, we want to make sure that we can find out what
this person, what this animal might be.
So, to lure out ET, they lay a trail of sweets, small round sweets, colored
round sweets. Okay?
And they lay the first one right at the edge of the woods.
They lay the next one, maybe a step or two ahead, and so on.
ET finds the first one, he picks it up, has a look at it, and tries it.
And he likes it. Okay?
In the second step, so he looks around if there are any more.
And he finds another one, takes the next one, likes it, and eats it.
And so on and so forth. So, he gets more and more excited, and
eventually, follows this trail of sweets into the bedroom of the kids.
When he picks up the last piece of sweets he picks it up, eats it, looks
up, because there are no more, the kids look up as well
and they start screaming, ET starts screaming and chaos ensues.
And so that's the story that you have to keep in mind.
What you may not know, is that the small pieces that ET picked up, were a small
candy called Reese's Pieces produced by a company called Hershey's.
Okay, and so, what I want to discuss now is the back drop to this story, the
commercial back drop to this particular story.
Okay, so we call it the chocolate wars.
And keep in mind, these are fictitious numbers that we're using.
Universal Studios, which were shooting ET at the time, they were charging, or
they were approaching Mars, saying, well, do you want to place a
product in this scene in ET? If you do, we're going to charge you
$1 million for that. If that had happened, if Mars had agreed
to that offer, then Mars' gross profits would have increased by 0.8
million, so 800,000 and Hershey's would have decreased by
100,000. So, to find the net profits, we have to
include the payment for that, which is 1 million.
So, Mars' gross profits would have been minus 0.2 million.
Hershey's, they didn't pay anything, and they suffered, 100,000 in loss of
sales. If product placement had taken place by
Hershey's, which is actually what took place, what happened, Hershey's gross
products would increase by 1.2 million and Mars' profits decrease by
0.5 million. So again, if we calculate the net
profits, this is going to be 1.2 minus 1, and that's positive 200,000.
If there's no product placement, it's just business as usual, nothing changes,
no profits change. So, that situation, obviously,
is something that was highly strategic because what happened depended on what
the other firm did, and so on and so forth.
So, how do we draw this? We can't really draw a matrix, as we'll
see in a second. So, how do we take into account the fact
that we have sequential decisions here? We draw what's called a game tree.
A game tree has the property that the first decision point always starts the
game. This decision point, and every decision
point that follows represents a node. And from that node, we have decisions of
subsequent players, subsequent decisions will branch out accordingly.
Okay, sounds very complicated, it's actually very easy and I want to take
that example of of Mars and Hershey's to illustrate this.
So, the first decision was Mars', okay? Mars got the offer from Universal
Studios, and they had the offer of either placing their product or not placing
their product, okay. After that, the decision came to
Hershey's. If product placement actually takes
place, if Mars signs the contract, then Hershey's can't really do anything, all
right. So, for them, it's just a question of
maintaining the status quo. If Mars does not agree to the deal, then
Hershey's again, has the choice between choosing product placement, so signing
the contract or not. Okay, so that's the structure of the
game. The next thing we need to know is what
the payoffs are. So, the payoffs if Mars signs and
Hershey's doesn't get to sign are plus 800,000 minus 1 million.
That's Mars' profits are going to be minus 0.2 million.
Hershey's, as we saw, are going to be minus 0.1.
If Mars doesn't sign, but Hershey signs instead
then Mars is going to lose half a million and Hershey's is going to win
200,000. Their net profits are going to increase
by 200,000. And if neither of them signs, they both
get profits of zero. Okay, so that would be a structure that
we can then go ahead and analyze, and we'll do that in the next video.
But for now, what this is useful for is, it can tell us
something about a strategy. What do we need to know if we want to
define a strategy of a game? So, we sort of have an idea already.
Alright, we have a working definition for this course which was, it's a player's
plan of actions in a particular game. But we need to extend this because we
need to take into account that these are actions for every possible circumstance of
this game. Okay, so in the case of ET
and Hershey's and Mars we'll get to that later in the next exercise.
Let's now have a look at price setting, okay?
Price setting, we have a sequential game, where Firm A first chooses a high or
low strategy. And then, Firm B chooses a high or low
strategy depending on whether Firm A has chosen high or low.
So, what are the possible strategies, the potential strategies for player B, okay?
We actually have four strategies for player B.
So, what are they? They are high, if high, and high, if low.
What does that mean? It means that if Firm A chooses a high
price, Firm B is going to choose a high price as well.
And if Firm A chooses a low price, Firm B is going to choose a high price
again. So that's one strategy.
What's the second strategy? Second strategy would be high, if high,
and low, if low. In that case, if Firm A chooses high,
Firm B is going to choose high, as well. If Firm A chooses low, then Firm B is
going to choose low, as well. Okay.
And you can figure out what the other two strategies for player B are.
Interestingly, if you compare this to Firm A, Firm A only has two strategies,
they can either choose high or low. They can't make this dependent on what
Player B does because Player B chooses later than Player A.
Okay? So, in this short video, we've analyzed
the product placement story of Mars and Hershey's as an example of a sequential
game. We've drawn up a game tree
and we've used it to systematically illustrate the competitive situation of
Mars when they are offered the product placement deal.
So, in the following video, we'll try to use the game tree to help find the
optimal strategy in a competitive situation.
But please first, do the in-video quiz. So, we've learned, in most cases, firms
can choose between different strategies. And so, please now, have a look at the
following game tree and take which strategies seem reasonable for Firm B,
okay? And I'll see you in the next video.
