As Supply decreases, the price increases and the quantity decreases

當供給下跌時，價格上升而數量下跌

P

Q

S2

P2

Q2

S1

P1

Q1

D

When fewer fishermen go fishing, ……

Case 1: Both S & D decrease

D1

P

Q

D2

P2

Q2

P1

Q1

S

When fewer people go to the market to buy fresh fish, ……

As Demand decreases, both the price and the quantity decrease

當需求下跌時，價格及數量下跌

P

Q

S2

S1

Q1

D1

P2

Q2

D2D2

P2=

Q2

D2

P2

Q2

The quantity of fish must decrease.

The change in price depends.

P1

Price increasesS > D

P

Q

S2

S1

P1

Q1

D1

P2

Q2

D2D2

P2=

Q2

D2

P2

Q2

when

Price is unchangedS = D

Price decreasesS < D

Case 2: Both S & D increase

P

Q

S2

S1

Q1

D1

P2

Q2

D2

P1

D2

P2=

Q2

D2

P2

Q2

When technological improvement saves cost, ……When the price of petroleum falls, ……

The quantity must increase.

The change in price depends.

Case 3: D decreases & S increases

W

E

S2

W2

E2

S1

W1

E1

D

When Vietnamese are allowed to find jobs, ……

As Supply of labour increases, the wage decreases and the employment increases

當供給上升時，薪金下跌而就業上升

D1

W

E

D2

W2

E2

W1

E1

S

When mechanization(機械化 ) is successful, ……

As Demand for labour decreases, both the wage and the employment decrease

當供給下跌時，薪金及就業兩者都下跌

D1

W

E

W1

E1

S1

S2

The wage of workers must decrease.

D2

W2

E2

Employment increasesS > D

when

D2

W2

E2

Employment is unchangedS = D

D2

W2

E2

Employment decreases

S < D

  After the completion of a new highway, the travelling time between Tin Shui Wai and Central will be much shortened. In addition, more land in Tin Shui Wai will be provided for building private housing.

Mr Ip thinks that the prices of private housing in Tin Shui Wai will increase due to the combined effects of the above government policies. With the aid of a supply-demand diagram, explain the circumstance under which Mr Ip would be right.

(7 marks)

Demand increases because of the easy traffic (1)

P

Q

S2

S1

Q1

D1

P1

D2

P2

Q2

Supply increases because of the increase in land (1)The increase in demand > the increase in supply (2)

2003年 11月 13日　星期四　明報港聞

Water samples were collected in the wholesale (批發 ) fish market in Aberdeen. The amount of Escherichia coli (大腸桿菌 ) found in the samples (樣本 ) was over the safety standard. Explain, with the aid of a diagram, how the price and the quantity of fish in the Aberdeen wholesale fish market are affected.

D1

P

Q

D2

P2

Q2

P1

Q1

S

in the Aberdeen wholesale fish market

The demand for fish in the Aberdeen wholesale fish market decreases.

The price decreases.

The quantity decreases.

The restaurant owner no longer buy seafood in the Aberdeen wholesale fish market. They buy seafood in Sai Kung. Explain with the aid of a diagram how the price and the quantity of seafood in Sai Kung are affected.

D1

P

Q

D2

P2

Q2

P1

Q1

S

in the Sai Kung seafood market

The demand for fish in the Sai Kung seafood market increases.

The price increases.The quantity increases.

Explain why the government worries the immediate suspension (禁制 ) of wholesale fish market operation (經營 ) in Aberdeen will affect the price of fish. How do the price and the quantity of fish change?

P

Q

S2

P2

Q2

S1

P1

Q1

D

The supply of fish decreases.

The price increases.

The quantity decreases.

Suppose now the operation of Aberdeen wholesale fish market is banned. At the same time, we know that there are fewer people consume seafood in the restaurants.

Some people expect the price of seafood will increase. Use a diagram to explain how the above two events would lead to an increase in price of seafood.

P

Q

S2

S1

Q1

D1

P2

Q2

D2

P1

The suspension of the fish wholesalers’ operation will lead to an increase in the price of fish. Explain why, with the help separate diagrams, the suspension of the fish wholesalers ’ operation leads to unemployment.

P

Q

S2

P2

Q2

S1

P1

Q1

D

The supply of fish decreases.

The price increases.

The quantity decreases.

D1

W

E

D2

W2

E2

W1

E1

S

Question: How will the price and quantity of Ah Mei’s (張惠妹 ) pirated CDs change when there is a ban on her album in mainland china and at the same time the Customs Department strictly enforces penalty to the pirated CD sellers and destroys the pirated CDs?

如果在中國大陸張惠妹的正版唱片遭封殺，而同時內地的海關執法部門嚴打翻版唱片的售賣，以及把搜出的翻版唱片全數銷毀

試指出上述兩項事件對張惠妹的翻版唱片的價格和銷售量有何改變

Question:

Under the influence of David Beckham being employed in promotion of the Soccer product, Lunar Predator Mania, the product become the favorite choice of the leisure soccer players.

However, the product is made of kangaroo skin and the punishment for killing kangaroos now become heavier. The supply of kangaroo skin becomes fewer.

Draw a Demand-Supply diagram to show there is an increase in the quantity transacted of Lunar Predator Mania.