00:00
Each year, trillions of dollars
worth of goods and services arrive in the
United States, and trillions of dollars worth of
goods and services leave.
每年，價值數兆美元的商品和服務進入美國，同時價值數兆美元的商品和服務出口。
00:12
Trade is one of the most
important economic concepts because trade allows
us to specialize - to focus on producing fewer
types of goods and services,
貿易是最重要的經濟概念之一，因為貿易讓我們能夠專業化——專注於生產較少種類的商品和服務，
00:23
which leads to increases in
productivity and increased productivity leads to better
and less expensive goods and services.
這將提高生產力，而生產力的提高又會帶來更好且更便宜的商品和服務。
00:33
Sounds great, right?
聽起來很棒，對吧？
00:34
Well, even though global trade
is beneficial in the aggregate - not everyone
benefits from it.
然而，儘管全球貿易整體上有益，但並非所有人都能從中受益。
00:41
When competition increases and
products become less expensive, not everyone wins.
當競爭加劇且產品變得更便宜時，並非每個人都是贏家。
00:48
Let's look at a simple example
in the market for coffee.
讓我們來看一個咖啡市場的簡單例子。
00:53
Imagine that trade only occurs
between buyers and sellers in country A.
想像一下，貿易只在A國的買家和賣家之間進行。
00:58
So there's no global trade.
因此，沒有全球貿易。
01:02
And let's look at
this graphically.
讓我們用圖表來看一下。
01:04
On the X axis,
we have pounds in millions and on the Y axis,
we have the price.
在X軸上，我們有百萬磅的數量，在Y軸上，我們有價格。
01:11
The equilibrium price
is $4 per pound.
均衡價格是每磅4美元。
01:15
And the equilibrium quantity
is 2 million pounds of coffee.
而均衡數量是200萬磅的咖啡。
01:20
Now let's introduce trade
with other countries.
現在，讓我們引入與其他國家的貿易。
01:24
First, we'll imagine
other countries can grow and manufacture
coffee at a lower price.
首先，我們假設其他國家能以更低的價格種植和製造咖啡。
01:31
In this case, the price
in the world market is below the price in
the domestic market.
在这种情况下，世界市場的價格低於國內市場的價格。
01:37
So the rest of the
world is selling it at $3 per pound,
not $4, as shown here with this horizontal line.
因此，世界其他地區以每磅3美元的價格銷售，而不是4美元，如這條水平線所示。
01:47
Note we'll assume that
country A is relatively small and can't really
affect the world price.
注意，我們假設A國相對較小，無法真正影響世界價格。
01:53
Now, if trade is allowed
and the less expensive goods are imported into country A, the domestic price
現在，如果允許貿易，並且更便宜的商品被進口到A國，國內價格
02:01
will eventually decrease
to equal the world price.
最終將下降至與世界價格相等。
02:05
Coffee buyers in
country A will now move from buying 2 to 2.5
million pounds of coffee at the new lower price.
國家A的咖啡買家現在會因為新的較低價格，從購買200萬磅增加到250萬磅咖啡。
02:15
When the world price is
below the domestic price, domestic consumers
gain from trade.
當世界價格低於國內價格時，國內消費者會從貿易中受益。
02:22
So if you're a coffee
buyer in country A, that's great news for you.
因此，如果你是國家A的咖啡買家，這對你來說是個好消息。
02:27
For those who are already
willing to buy coffee at that higher price, they're now getting it
at a lower price.
對於那些已經願意以較高價格購買咖啡的人來說，他們現在可以以更低的價格買到。
02:35
So this increases their
buyer or consumer surplus.
因此，這增加了他們的買家或消費者剩餘。
02:40
Now, recall,
the consumer surplus is the difference
between the maximum price a buyer would be willing to
pay and that market price.
現在回想一下，消費者剩餘就是買家願意支付的最高價格與
02:52
So, for example,
say you're willing to pay $7 for a pound of coffee, but the price of coffee
is only $4.
例如，假設你願意支付7美元購買一磅咖啡，但咖啡價格只有4美元。
03:01
Your consumer surplus
is the difference, $3.
你的消費者剩餘就是這個差額，3美元。
03:08
You got the coffee and
only had to pay $4.
你買到了咖啡，而且只付了4美元。
03:12
Or as another example,
imagine you're willing to pay $5 for coffee
but the price is only $4.
或者舉另一個例子，假設你願意支付5美元購買咖啡，但價格只有4美元。
03:20
Your consumer surplus
is $1 in this instance.
這時你的消費者剩餘是1美元。
03:26
And total consumer
surplus is summing up all individual consumer surplus.
而總消費者剩餘是所有個別消費者剩餘的總和。
03:33
Before trade,
total consumer surplus was represented by
this triangle, CS1.
在貿易之前，總消費者剩餘由這個三角形CS1表示。
03:39
But, by allowing trade,
consumer surplus increased to include
this entire area.
但是，通過允許貿易，消費者剩餘增加到包括整個區域。
03:46
Consumer surplus
increased for two reasons.
消費者剩餘增加有兩個原因。
03:50
First, consumer
surplus increased for buyers who were already
willing to purchase coffee because now they can enjoy the
same item at a lower price.
首先，消費者剩餘增加是因為那些已經願意購買咖啡的買家，現在可以以更低的價格享受相同的商品。
04:02
This increase in consumer
surplus is show here at CS2.
這種消費者剩餘的增加，在此處以CS2表示。
04:08
Second, the lower price makes
it possible for some buyers who wouldn't have bought coffee at
the higher price to now buy it.
其次，較低的價格使一些在較高價格下不會購買咖啡的買家現在可以購買。
04:17
This increases
consumer surplus too.
這也增加了消費者剩餘。
04:20
It allows for more
trades that wouldn't have occurred at the higher
price and is shown here at CS3.
這促成了更多在較高價格下原本不會發生的交易，並在圖中
04:29
In sum, consumer surplus
increased by this amount of both CS2 and CS3.
總之，消費者剩餘增加了CS2和CS3的總額。
04:37
But who loses?
但是誰損失了呢？
04:39
Domestic sellers.
本地賣家。
04:41
When the world price is
below the domestic price, domestic sellers
lose from trade.
當世界價格低於本地價格時，本地賣家因貿易而受損。
04:48
The new equilibrium
price is lower than the price before trade
with the rest of the world, as shown by the
movement from $4 to $3
新的均衡價格比與世界其他地區貿易前的價格更低，如圖所示，從4美元降至3美元
04:59
per pound and domestic
sellers sell less coffee.
每磅，且本地賣家銷售的咖啡更少。
05:04
Originally, they sold
2 million pounds of coffee and now they're selling only
1.5 million pounds of coffee.
原本他們銷售了200萬磅咖啡，現在只銷售150萬磅咖啡。
05:12
Recall that a seller's
gain from trade known as seller or
producer surplus, is the difference between
the market price of an item
回顧一下，賣家從貿易中獲得的收益，即賣家或生產者剩餘，是指商品的市場價格
05:22
and the lowest price they'd be
willing to sell that item for.
與他們願意出售該商品的最低價格之間的差額。
05:26
Originally their surplus was
shown by this blue shaded triangle, PS1 and PS2 combined, but by allowing trade
with other countries,
原本他們的剩餘是由這個藍色陰影三角形（PS1 和 PS2 加
05:34
it fell to this smaller
area of just PS2.
它縮減到只剩下PS2這個較小的區域。
05:39
When the world price is
below the domestic price, world sellers gain from trade.
當世界價格低於本地價格時，世界賣家從貿易中受益。
05:46
So if domestic coffee
sellers are only selling 1.5 million
pounds of coffee, but domestic buyers are buying
2.5 million pounds of coffee
所以，如果國內咖啡賣家只賣出150萬磅咖啡，但國內買家卻買進250萬磅咖啡
05:56
where is this extra million
pounds of coffee coming from?
這多出的100萬磅咖啡從哪裡來？
06:00
Sellers from other countries
are making up the difference.
其他國家的賣家彌補了這個差額。
06:03
An additional 1 million
pounds of coffee were imported into country A.
額外的100萬磅咖啡被進口到A國。
06:09
Total domestic surplus
increases from trade.
貿易增加了國內總剩餘。
06:12
Now recall that even though
domestic sellers lose surplus, total economic surplus for the
domestic country has increased.
現在回顧一下，儘管本地賣家的剩餘減少，但本地國家的總經濟剩餘已經增加。
06:21
Here is total surplus,
both sellers and buyers before opening up trade
with other countries.
這是開放與其他國家貿易前，買賣雙方的總剩餘。
06:29
And here is total surplus, after opening up trade
with other countries.
而這裡是在與其他國家開放貿易後的總剩餘。
06:34
So we can now see
that this area here marks the gains from trade,
newly created surplus as a result of trade.
所以我們現在可以看到，這裡的區域標示著貿易的利益，也就是貿易所創造的新增剩餘。
06:44
And here is where
seller surplus is simply being transferred to consumers.
而這正是賣方剩餘單純轉移給消費者的情況。
06:51
Now, well it may not
seem like a big deal since the surplus was
simply transferred from seller to buyer.
現在看來這似乎沒什麼大不了，因為剩餘只是從賣方轉移到買方。
06:58
That decrease in seller
surplus represents sellers scaling back production
and laying off employees.
賣方剩餘的減少代表著賣方正在縮減產量並裁員。
07:06
So, despite the
fact that expanding trade increases total
surplus in the aggregate, not everyone
welcomes this trend.
因此，儘管擴大貿易總體上增加了總剩餘，但並非所有人都歡迎這種趨勢。
07:16
The gains from trade
are unevenly distributed and some individuals
will be hurt.
貿易的利益分配不均，有些人會因此受損。
07:23
Because not everyone wins, Governments sometimes
restrict trade, usually to protect domestic industries
or workers from competition.
因為並非人人都能從中獲益，政府有時會限制貿易，通常是為了保護國內產業或勞工免受競爭。
07:34
One way they do so is by
enacting a tariff, essentially a tax paid only
by foreign sellers on certain types of goods
or services imported
他們這樣做的方式之一，就是課徵關稅，關稅本質上是一種只
07:43
into the country.
進入該國。
07:45
This raises
foreign sellers’ costs and ultimately increases the
world price from here to here.
這會提高外國賣家的成本，並最終將此處到此處的世界價格推升。
07:52
In this example, the tariff
increased the price of coffee from $3 to $3.50.
在本例中，關稅使咖啡價格從3美元提高到3.5
08:00
In general,
trade restrictions such as tariffs, lead to more domestic production
and fewer imports.
一般而言，關稅等貿易限制會導致國內生產增加，進口減少。
08:08
When compared with
open trade restrictions result in higher prices,
as shown here, and fewer goods
sold as shown here.
相較於開放貿易，貿易限制會造成價格上漲（如圖所示），且
08:18
Economists generally support
open international trade because it increases the overall
productivity and surplus.
經濟學家普遍支持開放國際貿易，因為這能提升整體生產力及剩餘
08:27
In summary, international
trade increases because economic
surplus increases.
總而言之，國際貿易之所以會增加，是因為經濟剩餘有所提升。
08:32
In this example,
domestic consumers benefit through lower prices
and more coffee purchased.
在這個例子中，國內消費者受惠於更低的價格，並能購買到更多的咖啡
08:38
But not everyone wins.
但並非所有人都受益。
08:41
Increases in competition mean
that some businesses can't sell at that lower price
and that many workers at those businesses
will lose their jobs.
競爭加劇意味著，有些企業無法以那樣的低價銷售，而這些
08:51
While tariffs seem like
an obvious solution, because they support
domestic sellers and workers, they result in an inefficient
use of resources leading
雖然關稅看似是個顯而易見的解決方案，因為它們能
09:00
to higher prices for consumers
and fewer goods sold - and ultimately a decrease
in economic surplus.
造成消費者物價上漲、商品銷售量減少，最終導致經濟剩餘的下降。
09:09
EconLowdown.
經濟學速成。
09:10
Click. Teach.
點擊。教學。
