Name: 供求關係：一杯咖啡背後的力量 (Supply and Demand: The Force Behind a Cup of Coffee)
Uploaded: 2025-08-02T18:06:01.000Z
Duration: 6 min 41 s

Welcome to our short course in economics, where we learn how we make choices when unlimited human wants meet limited resources.

歡迎來到我們的經濟學短期課程，在這裡我們將學習當人類無限的需求與有限的資源相遇時，我們如何做出選擇。

動名詞

Supply and demand shows how people coordinate their decisions by communicating through prices.

供求顯示了人們如何通過價格溝通來協調決策。

Supply refers to the number of goods and services that sellers produce at a certain price.

供應是指賣方以一定價格生產的商品和服務的數量。

Demand refers to how many goods and services consumers are willing to buy at a certain price.

需求是指消費者願意以一定價格購買多少商品和服務。

Let's assume there is just one coffee shop on the market, but 100 people who drink coffee.

假設市場上只有一家咖啡店，但有 100 個人喝咖啡。

The price of coffee is $3 per cup, and the people each drink one cup per day.

咖啡的價格是每杯 3 美元，人們每人每天喝一杯。

We can illustrate this with a diagram showing the price per cup of coffee on the vertical axis and the number of cups of coffee consumed on the horizontal axis.

我們可以用一張圖來說明這一點，縱軸是每杯咖啡的價格，橫軸是消耗的咖啡杯數。

How many cups of coffee would these 100 people drink if the price of a cup were to increase to $8?

如果一杯咖啡的價格上漲到 8 美元，這 100 個人會喝多少杯咖啡？

While at $3, 100 people drink a cup of coffee, at $8, maybe just 30 do.

3 美元一杯的咖啡有 100 人喝，而 8 美元一杯的咖啡可能只有 30 人喝。

And at $12, there could be as few as 10 people interested in purchasing a cup.

而 12 美元的價格，可能只有 10 個人有興趣購買一杯。

However, at $1 per cup, demand could go up to 150 cups a day because some of those original 100 customers are now drinking two or more cups.

但是，如果每杯 1 美元，每天的需求量可能會增加到 150 杯，因為原來的 100 位顧客中有些人現在會喝兩杯或更多。

This is what economists call a demand curve.

這就是經濟學家所說的需求曲線。

It shows how much quantity is in demand at each price.

它顯示了每種價格下的需求量。

The curve usually slopes downwards because economists assume that the lower the price, the higher the quantity demanded.

曲線通常向下傾斜，因為經濟學家認為價格越低，需求量越大。

The supply curve shows the number of goods or services sellers are willing to provide at a given price.

供應曲線顯示了賣方願意以給定價格提供的商品或服務數量。

It curves upward because the higher the price, the more supply.

曲線向上是因為價格越高，供應越多。

As we already know, at $1, the people on the market demand 150 cups a day.

我們已經知道，以 1 美元計算，市場上的人每天需要 150 杯。

However, the owner already pays $1.20 for the beans per cup, which means he can't sell a cup for just $1.

然而，店主已經為每杯咖啡豆支付了 1.20 美元，這意味著他不能只賣 1 美元一杯。

If the price were to be $12 per cup, the owner could hire two additional staff while supplying up to 150 cups.

如果每杯的價格是 12 美元，店主就可以多僱兩名員工，同時供應多達 150 杯飲料。

Unfortunately, only 10 customers would buy at this price, and that's not enough to cover the cost of business.

遺憾的是，這個價格只有 10 個客戶會購買，不足以彌補經營成本。

At this cost, the owner can hire one employee and happily supply the 100 cups a day that are demanded at that price.

按照這個價格，店主可以僱用一名員工，每天欣然供應 100 杯需求量。

Supply and demand on one graph look like this.

一張圖上的供求關係是這樣的。

At $12, the owner can supply 150 cups, but only 10 people would buy a cup of coffee at that price.

12 美元的價格，店主可以提供 150 杯咖啡，但只有 10 個人會以這個價格購買一杯咖啡。

At $1, he can't supply any, but demand would be 150 cups of coffee.

按 1 美元計算，他無法提供任何咖啡，但需求量將達到 150 杯。

兩條曲線在 3 美元和 100 杯處交匯。

現在讓我們假設情況發生了變化。

The summer was very hot, and there was only a little rain which left many coffee bean crops destroyed.

夏天非常炎熱，雨水稀少，許多咖啡豆作物被毀。

The poor harvest yielded a low supply of beans.

As a result, more traders bid for the limited amount of beans, leading to an increase in  The shop owner now buys the beans from the farmer at $2 for the beans per cup.

是以，更多的商人競相購買有限的豆子，導致豆子價格上漲。

He tries and decides to let go of his employee and begin serving coffee all by himself.

他試了試，決定放手讓員工去做，自己一個人開始端咖啡。

But he cannot meet the demand of all his customers.

但他無法滿足所有客戶的需求。

If the government were to force him to keep the price fixed through so-called price controls, queuing would be part of everyone's life.

如果政府通過所謂的價格控制迫使他把價格固定下來，那麼排隊就會成為每個人生活的一部分。

To reduce the wait times for his clients and make up for the increased cost of the beans, the owner decides to increase the price of the coffee to $4.50.

為了減少顧客的等待時間，彌補咖啡豆成本的增加，店主決定將咖啡價格提高到 4.50 美元。

The supply curve now shifts to the left, and at $4.50, the shop will sell 70 cups of coffee per day.

現在，供應曲線向左移動，以 4.50 美元計算，該店每天將售出 70 杯咖啡。

Typically, the higher the selling price of a good, the greater number of people willing to supply it.

通常情況下，商品售價越高，願意供應的人就越多。

This means that there will likely be more competition soon.

這意味著，很快就會有更多的競爭。

In real life and within a free market, if you drink coffee at $4.50, it's not the basis of an economic calculation, but the result of an endless dance of trial and error between sellers and buyers that lead them to reach an unspoken agreement about what works best for both.

在現實生活和自由市場中，如果你以 4.50 美元的價格喝咖啡，這並不是經濟計算的結果，而是賣方和買方之間無休止地試錯的結果，是他們就什麼對雙方最有利達成的不言而喻的協議。

This phenomenon is referred to as emergent order.

Before we summarize, please note that economists differentiate between quantity demanded and demand.

在總結之前，請注意經濟學家對需求量和需求量的區分。

A change in the quantity demanded happens due to a change in price, like we explored when the price dropped and the quantity demanded increased.

需求量的變化是由價格變化引起的，就像我們探討的價格下降而需求量增加的情況。

A change in demand happens when the environment changes.

當環境發生變化時，需求也會發生變化。

Let's imagine that many people in the market become more health-conscious and think that coffee is bad.

假設市場上很多人越來越注重健康，認為咖啡不好。

If that happens, the entire demand curve shifts downward, and at $3, not 100 buy coffee, but just 40.

如果出現這種情況，整個需求曲線就會向下移動，3 美元的價格就不會有 100 人購買咖啡，而只會有 40 人購買。

Supply is the amount provided at each price.

供應量是指在每種價格下提供的數量。

Demand is the amount purchased at each price.

需求量是指以每種價格購買的數量。

The final price is the result of an emergent order.

If you are up for it, we will now ask you to help us understand today's price of coffee.

如果您願意，我們現在請您幫助我們瞭解今天的咖啡價格。

Post your thoughts in the comments below.

請在下面的評論中發表您的看法。

Search for a coffee price chart and you'll find a graph showing the price of coffee in US dollars.

搜索 "咖啡價格圖表"，您會發現一張顯示咖啡美元價格的圖表。

Then tell us, what's the price of 1 kg of coffee today?

那麼請告訴我們，今天 1 公斤咖啡的價格是多少？

What do you think are the reasons that have caused the price to fluctuate in the past 5 years?

您認為造成過去 5 年價格波動的原因是什麼？

This and all other Sprouts videos are licensed under Creative Commons.

本視頻及其他所有 Sprouts 視頻均採用知識共享許可協議進行許可。

That means teachers from all around the world can use them in classrooms, online courses or to start projects, and today thousands already do.

這意味著世界各地的教師都可以在課堂、在線課程或啟動項目中使用它們，如今已有成千上萬的教師這樣做了。

To learn how it works and download this video without ads or background music, check out our website or read the description below.

要了解其工作原理並下載這段無廣告或背景音樂的視頻，請訪問我們的網站或閱讀下面的說明。

If you want to support our mission and help change education, visit our Patreon.

如果您想支持我們的使命並幫助改變教育，請訪問我們的 Patreon。

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供求關係：一杯咖啡背後的力量 (Supply and Demand: The Force Behind a Cup of Coffee)

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