新高中經濟學課程學與教策略系列：
(1) 建構式學習方法(重辦課程)
討論問題
• 你有否應用類似的教學方法於這課題上，
抑或還有其他方法？若有的話，請分享。
若果沒有，為什麼不採用呢？
Double-auction experiment
• The first market experiment was
conducted by Chamberlain (1948)
• Vernon Smith, a participant in one of
Chamberlain's experiments, modified it
and created the double auction
• It is an experiment trying to simulate
forces of demand and supply in a market
 You’ll be given the following:
i) a label which shows whether you’re a
buyer (red) or a seller (blue)
ii) a piece of paper which shows either your
value / cost, and allows you to record the
trading information after each round
 There’ll be around 3-4 rounds of trading.
Each round lasts for about 5 minutes.
Each round of trading is a new one.
Your objective:
Get as much “gain” as possible:
buyer’s gain OR seller’s gain
You don’t have to trade with others
if you can’t find chances of
profitable trade.
 Don’t trade at a loss!
• You don’t have to reveal your cost / value
• After trading, please go to the “market
manager”, get a green form and provide
the following information : 1) trading price
2) buyer value and seller cost
• Don’t be “shy”. Just “shout”!
• If you can’t find trading partners for long,
don’t give up; just keep on searching,
using all market information available
• Don’t always stick with the same person
throughout the game
Incentives:
• The top 2 buyers and top 2 sellers with the
highest gains will have a special prize.
ROUND 1
Price($)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
Mean price($)
#DIV/0!
Total buyers' gain($)
0
Buyer value($) Seller cost($)
Buyer gain($) Seller gain($)
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Standard deviation
#DIV/0!
Total sellers' gain($)
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
ROUND 2
Price($)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
Mean price($)
#DIV/0!
Total buyers' gain($)
0
Buyer value($) Seller cost($)
Buyer gain($) Seller gain($)
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Standard deviation
#DIV/0!
Total sellers' gain($)
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
ROUND 3
Price($)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
Mean price($)
#DIV/0!
Total buyers' gain($)
0
Buyer value($) Seller cost($)
Buyer gain($) Seller gain($)
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Standard deviation
#DIV/0!
Total sellers' gain($)
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
ROUND 4
Price($)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
Mean price($)
#DIV/0!
Total buyers' gain($)
0
Buyer value($) Seller cost($)
Buyer gain($) Seller gain($)
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Standard deviation
#DIV/0!
Total sellers' gain($)
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
• Discuss the following questions (If time doesn’t allow you
to finish all, just do Questions 1-2)
• 1. What are the strengths and limitations of this
experiment?
• 2a. What economic concepts are involved in this
experiment?
b. Suppose you have used this game to illustrate a
certain/some economic concepts in a lesson.
After playing the game with the class, think of about
4-5 questions that you would put in a worksheet or
you would ask.
3. (optional) How can this game be modified to
illustrate more economic concepts?
ROUND 1
Names
1 Cc
2 Db
3 Aa
4 Bd
5
Mean price($)
Total seller's gain($)
Total buyer's gain($)
ROUND 2
Names
1 Ec
2 Ab
3 Be
4 Dd
5 Ca
Mean price($)
Total seller's gain($)
Total buyer's gain($)
ROUND 3
Names
1 Ea
2 De
3 Ad
4 Bc
5 Cb
Mean price($)
Total seller's gain($)
Total buyer's gain($)
Price($) Seller cost($) Buyer value($) Seller's gain($) Buyer's gain($)
30
23
40
7
10
30
23
45
7
15
30
18
45
12
15
20
18
40
2
20
0
0
27.5
Standard deviation
5
28
60
Price($) Seller cost($) Buyer value($) Seller's gain($) Buyer's gain($)
30
28
40
2
10
31
18
45
13
14
30
18
35
12
5
30
23
40
7
10
30
23
45
7
15
30.2
Standard deviation
0.45
41
54
Price($) Seller cost($) Buyer value($) Seller's gain($) Buyer's gain($)
31.5
28
45
3.5
13.5
29
23
35
6
6
30
18
40
12
10
31
18
40
13
9
31
23
45
8
14
30.5
Standard deviation
1
42.5
52.5
Results of an experiment done in a secondary school (16 participants)
Debriefing handout
Table A
Sellers’ and buyers’ information
Number in market
Buyer’s value
Number in market
Seller’s cost
$18
2
$45
2
$23
2
$40
2
$28
1
$35
1
$33
1
$30
1
$38
1
$25
1
$43
1
$20
1
Now use the information in Table A to complete the demand and supply schedule:
Price
Quantity supplied (units)
Price
Quantity demanded (units)
$18
2
$45
2
$23
4
$40
4
$28
5
$35
5
$33
6
$30
6
$38
7
$25
7
$43
8
$20
8
Topic
E Efficiency,
Equity and the
Role of
Government
Key Points
Efficiency
(i)
Conditions for efficiency: Maximization of total
social surplus; marginal benefit equals marginal cost.
(ii) Deviations from efficiency:
- Price ceiling, price floor, tax, subsidy and quota
- Deadweight loss
(iii) Divergence between private and social costs
(benefits):
market versus government solutions, illustrated by
examples ONLY
(N.B. Graphical analysis with illustration of consumer
surplus and producer surplus in a demand-supply
diagram only. The terminology “Pareto condition”
NOT required)
How will you explain to students
about the deadweight loss (or excess
burden) caused by taxes?
• Tax distorts incentives and hence people’s
behavior. People allocate resources
according to tax incentives, rather than the
true costs and benefits of the goods.
• For instance, if the government taxes
housing, people live in smaller houses and
spend more of their income on other things.
If the government taxes ice-cream, people
eat less ice-cream and more frozen yogurt.
Taxes and Efficiency
130
S + tax
Consumer
surplus
Price (dollars per CD player)
S
Tax
revenue
105
c
100
Deadweight
loss
95
0
D
Producer
surplus
75
1
2
3
4
5
6 7
8
9
10
Quantity (thousands of CD players per week)
• Tax prevents some
trades that would be
profitable for both
buyer and seller in the
absence of a tax.
• Consumers buy less
and producers
produce less. Market
size shrinks below the
optimum.
Do many students have difficulty in
understanding this concept?
What if some students still find
this concept too “abstract” to
understand?
Any other ways to make this concept
more concrete (especially to those with
the least abstract thinking ability)?
• In Session 1(where there’s no tax)
 Find the sum of total consumer and seller
surplus.
• In Session 2 (where tax is added), both
consumer and seller surplus decrease
because some goes to tax revenue.
 Again find the sum of consumer surplus,
seller surplus & tax revenue.
 Is the sum in Session 2 the same as that
in Session 1? Why?
P
Sellers Pay the Sales Tax
50
45
New Supply Curve
40
Original Supply Curve
35
New Equilibrium
30
25
Old Equilibrium
20
15
Demand Curve
10
5
0
Q
5
10
15
P
50
45
New Supply Curve
40
Original Supply Curve
35
New Equilibrium
30
25
Old Equilibrium
20
15
Demand Curve
10
5
0
5
10
15
Q
A: Consumer surplus
B: Seller surplus
C: Tax revenue
D: Deadweight loss
of a sales tax