管理经济学第二章02——需求、供给与市场均衡

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2.2.3 Inverse Supply Function （反供给函数）

Traditionally, price (P) is plotted on the vertical axis & quantity supplied (Qs) is plotted on the horizontal axis
2.2.2 Direct Supply Function （直接供给函数）

The direct supply function, or simply supply, shows how quantity supplied, Qs , is related to product price, P, when all other variables are held constant Q = f(P) s

The equation plotted is the inverse demand function, P = f(Qd)
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Graphing Demand Curves

A point on a direct demand curve shows either:


Maximum amount of a good that will be purchased for a given price Maximum price consumers will pay for a specific amount of the good
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Variable
General Demand Function
Relation to Qd
Sign of Slope Parameter
P M PR
Inverse Direct for normal goods Inverse for inferior goods Direct for substitutes
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。广义需求函数:六因素P,M,PR,J,Pe,N。


产品或服务的价格 消费者的收入 相关产品的价格 消费者的偏好 预期价格 消费者的数量
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General Demand Function
Qd a bP cM dPR e fPe gN

b, c, d, e, f, & g are slope parameters Measure effect on Qd of changing one of the

At the point of intersection, Qd = Qs Consumers can purchase all they want & producers can sell all they want at the “market-clearing” or price
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Market Equilibrium
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A Supply Curve
(Figure 2.3)
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2.2.4 供给量的变化与供给的变化

Change in quantity supplied

Occurs when price changes Movement along supply curve Occurs when one of the other variables, or determinants of supply, changes Supply curve shifts rightward or leftward
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General Supply Function
Variable Relation to Qs
Direct
Inverse
Sign of Slope Parameter
P
PI Pr T Pe F
k = Qs/P is positive
l = Qs/PI is negative
Inverse for substitutes
Taste patterns of consumers ( ) • Expected future price of product (Pe) • Number of consumers in market (N)
•
• General demand function
•
Qd f ( P, M , PR , , Pe , N )
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A Demand Curve (Figure 2.1)
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2.1.4 需求量的变化与需求的变化

Change in quantity demanded

Occurs when price changes Movement along demand curve Occurs when one of the other variables, or determinants of demand, changes Demand curve shifts rightward or leftward
(Figure 2.5)
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Market Equilibrium

Excess demand (shortage)

Exists when quantity demanded exceeds quantity supplied Exists when quantity supplied exceeds quantity demanded
Chapter 2
需求、供给与市场均衡
Demand,Supply,and Market Equilibrium
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Demand,Supply,and Market Equilibrium
2.1 需求 2.2 供给 2.3 市场均衡 2.4 市场交易的价值 2.5 市场均衡的变动 2.6 限制价与支持价
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Change in demand


Shifts in Demand
(Figure 2.2)
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2.2 Supply（供给）

Quantity supplied (Qs)（供给量）

Amount of a good or service offered for sale during a given period of time
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Supply

Six variables that influence Qs

Price of good or service (P) Input prices (PI ) Prices of goods related in production (Pr) Technological advances (T) Expected future price of product (Pe) Number of firms producing product (F)
variables while holding the others constant

Sign of parameter shows how variable is related to Qs


Positive sign indicates direct relationship Negative sign indicates inverse relationship
variables while holding the others constant

Sign of parameter shows how variable is related to Qd

Positive sign indicates direct relationship Negative sign indicates inverse relationship

General supply function

Qs f (P, PI , Pr , T , P e , F)
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2.2.1 General Supply Function （广义供给函数）
Qs h kP lPI mPr nT rPe sF

k, l, m, n, r, & s are slope parameters Measure effect on Qs of changing one of the

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2.1.1 General Demand Function （广义需求函数）

Six variables that influence Qd

Price of good or service (P) Incomes of consumers (M) Prices of related goods & services (PR)
e = Qd/ is positive
f = Qd/Pe is positive
N
Direct
g = Qd/N is positive
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2.1.2 Direct Demand Function （直接需求函数）


The direct demand function, or simply demand, shows how quantity demanded, Qd , is related toLeabharlann Baiduproduct price, P, when all other variables are held constant Qd = f(P) Law of Demand

The equation plotted is the inverse supply function, P = f(Qs)
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Graphing Supply Curves

A point on a direct supply curve shows either:


Maximum amount of a good that will be offered for sale at a given price Minimum price necessary to induce producers to voluntarily offer a particular quantity for sale
Inverse for complements
b = Qd/P is negative c = Qd/M is positive c = Qd/M is negative d = Qd/PR is positive d = Qd/PR is negative

Pe
Direct
Direct
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2.1 Demand(需求)

Quantity demanded (Qd)（需求量）

Amount of a good or service consumers are willing & able to purchase during a given period of time
一个特定时期内，消费者对一种商品，愿意而且能 够购买的数量。
Direct for complements
m = Qs/Pr is negative m = Qs/Pr is positive
n = Qs/T is positive r = Qs/Pe is negative s = Qs/F is positive
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Direct Inverse Direct
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Change in supply


Shifts in Supply
(Figure 2.4)
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2.3 Market Equilibrium（市场均衡）

Equilibrium price & quantity are determined by the intersection of demand & supply curves
Qd increases when P falls & Qd decreases when P
rises, all else constant Qd/P must be negative
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2.1.3 Inverse Demand Function （反需求函数）

Traditionally, price (P) is plotted on the vertical axis & quantity demanded (Qd) is plotted on the horizontal axis