I mean, how would you recognize a perfectly competitive industry if you ran across one?

我的意思是，你怎麼會認識一個完美的 競爭激烈的行業，如果你碰到了？

In perfect competition, 1) there are a large number of sellers (there are a large number

在完美的競爭中，1）有大量的 賣家數量（有大量的）。

of buyers too, but we won't be worrying about that just now).

的買家，但我們不會擔心。 那剛才）。)

No individual is large enough to affect the market.

沒有任何一個個體大到足以影響 市場。

2) the product is homogeneous, or identical, or non-differentiated.

2）產品是同質的，或相同的。 或無差別的。

For example, milk.

比如，牛奶。

When you go to buy 2% milk at the supermarket, what brand do you buy?

當你去超市買2%的牛奶時。 你買什麼牌子的？

If you're like me, you buy whatever's on sale.

如果你像我一樣，打折的時候你就買什麼。

I have no brand loyalty whatsoever, because milk is milk.

我沒有任何品牌忠誠度，因為... 牛奶就是牛奶。

3) There's perfect information.

3）有完善的資料。

It's actually not enough for products to be identical; everyone has to know that the products

其實光有產品是不夠的，還要有 一模一樣；每個人都必須知道，這些產品

are identical.

是相同的。

Otherwise, we can be fooled by things like pretty packaging, or celebrity endorsements.

否則，我們就會被一些東西所矇蔽，比如說 漂亮的包裝，或者明星代言。

In a perfectly competitive industry, firm versus firm advertising is useless.

在一個完全競爭的行業中，公司 與公司廣告是沒有用的。

All you'd be doing is driving up your own costs, and then customers would just buy from

你所做的一切只是在抬高自己的身價。 成本，然後客戶就會直接從

a cheaper competitor.

一個更便宜的競爭對手。

However, you may see industry-wide advertising, like a “Got milk?”

不過，你可能會看到全行業的廣告。 像 "有牛奶嗎？"

campaign, “pork, the other white meat,” or “beef -- it's what's for dinner.”

運動，"豬肉，另一種白肉" 或 "牛肉... ... 這就是晚餐的內容。"

These kinds of campaigns raise demand for each firm's product across the industry.

這類運動提高了對 每家公司的產品在行業內。

4) Easy entry and exit.

4）進出方便。

Because firms can enter and exit the industry at will, long-term profits would be affected,

因為企業可以進入和退出這個行業 隨意，長期利潤會受到影響。

but we'll get to that in just a bit.

但我們會得到在只是一點點。

For the individual firm owner, the combined effect of these characteristics is that he/she

對於個體工商戶來說，合 這些特徵的影響是，他/她

has no power to control price, and will earn zero economic profit in the long run.

沒有控制價格的權力，將賺取。 長期來看，經濟利潤為零。

Let me ask you this: If the individual firm cannot set the price, then where does the

讓我問你這個問題。如果個別公司 不能確定價格，那麼哪裡來的

price come from?

價格從何而來

Think back to our market activity earlier in the semester: in a market with lots of

回想一下我們之前的市場活動 學期中：在市場上有很多的

buyers and sellers, the price is determined collectively by the market supply and market

買賣雙方，價格決定 由市場供應和市場

demand.

需求。

This, then, is the prevailing price for each firm.

那麼，這就是每一個人的現行價格。 堅定的。

What happens if the firm doesn't like this price?

如果公司不喜歡這樣做會怎樣？ 價格？

If it tries to charge more than P*, all of the customers will go someplace else.

如果它試圖收取超過P*的費用，所有的 客戶會去別的地方。

So, the firm would be forced back down to P*.

所以，該公司將被迫回落到。 P*.

If it tries to charge less than P*, then all customers in the industry will come to this

如果它試圖收取低於P*的費用，那麼所有的 業內客戶會來此

firm.

堅定的。

Sounds good, right?

聽起來不錯吧？

Wrong.

錯了

This firm cannot accommodate the entire industry demand -- costs would skyrocket, and the firm

這家公司不能容納整個行業 需求--成本會急劇上升，而該公司

would be forced back up to P* to get rid of some of the customers.

將被迫回升到P*，以擺脫。 的一些客戶。

All of this means that the firm is a price taker, forced to accept P*, the market-determined

所有這些都意味著該公司是一個價 購房者，被迫接受市場決定的P*。

equilibrium price.

平衡價格。

Note that this also means, because the firm charges P* regardless of the quantity demanded,

請注意，這也意味著，由於該公司 無論需求量多少，均收取P*。

that P* represents the firm's demand, as well.

即P*代表企業的需求，也。

Remember that perfectly elastic demand curve from earlier this semester, where consumers

記住，完全彈性的需求曲線 從本學期初，消費者

are so hypersensitive to price that price is all that matters?

對價格過於敏感，以至於價格 是所有的問題？

Well that's this market structure.

嗯，這就是這個市場結構。

OK, so -- you're producer in a perfectly competitive market, and you have no control

好吧，所以... ...你是一個完美的製作人。 競爭市場，而你無法控制

over the price that you can charge.

超過你能收取的價格。

Is there anything you do have control over, that you can make decisions about?

有什麼事情是你能控制的嗎。 你可以做決定的？

A perfectly competitive firm may not be able to choose its price, but it can choose how

一個完全競爭的公司可能無法 選擇它的價格，但它可以選擇如何。

much output to produce.

多的產量來生產。

The firm owner will choose the level of output that will maximize his/her profits (see episode

企業主將選擇產出水準 將使他/她的利潤最大化（見劇情

26B to see why marginal revenue equals marginal cost will always be the profit maximizing

26B來看為什麼邊際收入等於邊際收入？ 成本永遠是利潤最大化

rule).

規則）。)

So – you're a firm owner in a perfectly competitive industry, you can't choose the

所以--你是一個完美的公司老闆。 競爭激烈的行業，你不能選擇

price that you charge, but you can select the amount of output that you produce.

的價格，但您可以選擇 你的產出量。

In order to maximize profit, you will always choose the level of output were marginal revenue

為了實現利潤最大化，您將始終 選擇邊際收入的產出水準

equals marginal cost.

等於邊際成本。

Take a look at the perfectly competitive firm and see where this occurs.

看看這個具有完美競爭力的公司 並看看這種情況發生在哪裡。

Hmmm…

嗯...

I need to choose output such that marginal revenue equals marginal cost, but right now

我需要選擇產出，使邊際 收益等於邊際成本，但現在

I don't see marginal revenue OR marginal cost!

我沒看到邊際收入或邊際成本!

Let's start with marginal revenue.

先說說邊際收入吧。

Marginal revenue is the additional revenue that you earn when you sell an additional

邊際收入是指額外收入 當您賣出一個額外的

unit of output.

產出組織、部門。

For a perfectly competitive firm, since all units are sold for the same price, each unit

對於一個完全競爭的公司，因為所有 組織、部門售價相同，每組織、部門

sold always adds the same amount of revenue, P*.

賣出的總是增加同樣的收入。 P*.

For example, if price is $5, then the total revenue for zero units is $0, for one unit

例如，如果價格是5元，那麼總的來說 0臺的收入為0元，1臺的收入為0元

is $5, for two units is $10, and so on.

是5元，兩個組織、部門是10元，以此類推。

Selling one more unit generates five additional dollars of revenue each time.

多賣出一個組織、部門就會多出5個 元的收入，每次。

Therefore marginal revenue is equal to the equilibrium price.

是以邊際收入等於 平衡價格。

Note that this is only true for perfect competition.

請注意，這隻適用於完美競爭。

What about marginal cost?

那邊際成本呢？

Well, marginal cost is actually pretty easy -- we constructed the cost curves, marginal

嗯，邊際成本其實很簡單 -- 我們構築了成本曲線，邊際成本

cost included, before knowing anything about market structures.

費用包括，在瞭解任何關於 市場結構；

Those cost curves in the same regardless of the structure we're operating in.

這些成本曲線是一樣的，無論 的結構，我們在經營。

This means that the marginal cost for the perfectly competitive firm is just… marginal

這意味著 完全競爭的公司只是... 邊際的

cost (remember that J-shaped, Nike-swish thing), and now all we need to do is select the level

成本（還記得那個J型，Nike-swish的東西）。 現在我們需要做的就是選擇級別的問題。

of output were marginal revenue equals marginal cost.

邊際收入等於邊際收入的產出。 費用：

Now, because there are no average cost curves in this diagram yet, I can't actually show

現在，因為沒有平均成本曲線。 在這張圖中，我還不能真正顯示出

you how large or small the profits are; only that q* will be the best level of output for

你的利潤有多大或有多小；只是 的最佳產出水準，即q*。

this particular producer, based on the profit-maximizing rule.

根據利潤最大化的原則，這個特定的生產者。 規矩

Let's look at just one example of how to find profit using this model, then we'll do more

讓我們看一個例子，如何找到 用這個模型來盈利，那麼我們會做更多的。

cases in class.

課堂上的案例。

What if my perfectly competitive producer is operating in an industry where price is

如果我的完美競爭生產商 是在一個價格是

greater than the cost per unit?

大於單位成本？

I can already tell that this producer will be making profits, since there's more coming

我已經看出，這個製作人將 賺錢，因為有更多的人要來了

in for each unit than there is being paid out in cost, but let's see what it looks like.

每組織、部門的收入比支付 出在成本上，但讓我們看看它是什麼樣子的。

Notice that I positioned the average cost curves below the price line.

請注意，我將平均成本定位為 價格線以下的曲線。

Where is MR = MC?

哪裡是MR=MC？

This gives me q*.

這樣我就有了q*。

At q*, what is the total revenue coming in?

在q*，總收入是多少？

Revenue is the price I can charge times the number of units that I sell.

收入是我可以收取的價格乘以 我銷售的組織、部門數量。

In this case, the green area.

在這種情況下，綠化區。

At q*, what's the total cost of producing this output?

在q*，生產的總成本是多少？ 這個輸出？

It's the cost per unit, ATC, times the number of units I sell -- in this case the red area.

它是單位成本，ATC，乘以數量。 的組織、部門 -- 在這種情況下，紅色區域。

The amount of revenue (in green) that doesn't get chewed up by the costs (in red) is profit.

收入的數量（綠色），不包括： 被成本(紅色)吞噬的是利潤。

In this case, I've indicated profit by the blue area.

在這種情況下，我已經表示利潤由 藍色區域。

In the short run, this producer earns positive profits.

在短期內，該生產商賺取正 的利潤。

Why do I say “in the short run”?

為什麼我說 "短期內"？

Because those short run profits attract the sharks -- other outside firms see the profits

因為這些短期利潤吸引了 高利貸 -- 其他外部公司看到了利潤

and enter the industry to set up shop.

並進入行業開店。

This causes industry supply increase, driving the price downward.

這就造成行業供給增加，帶動 的價格下調。

In the end, the entry only stops when there are no more profits to attract the sharks;

最後，只有當有以下情況時才會停止進入 是沒有更多的利潤來吸引鯊魚。

until price is equal to average total cost, and the firms just break even.

直到價格等於平均總成本。 而公司只是收支平衡。

In the long run, a perfectly competitive firm's profits are always equal to zero.

從長遠來看，一個完全競爭的公司的。 利潤永遠等於零。

NEXT TIME: Monopoly TRANSCRIPT00(MICRO) EPISODE 26: PERFECT COMPETITION

下一次：大富翁 TRANSCRIPT00(MICRO) EPISODE26: PERFECT COMPETITION(完美競爭)