Download presentation
Presentation is loading. Please wait.
1
Demand, Supply, & Market Equilibrium
Chapter 2 Demand, Supply, & Market Equilibrium
2
Demand Quantity demanded (Qd)
Amount of a good or service consumers are willing & able to purchase during a given period of time
3
Demand Six variables that influence Qd Generalized demand function
Price of good or service (P) Incomes of consumers (M) Prices of related goods & services (PR) Expected future price of product (Pe) Number of consumers in market (N) Generalized demand function
4
Generalized Demand Function
b, c, d, e, f, & g are slope parameters Measure effect on Qd of changing one of the 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
5
Generalized Demand Function
Variable Relation to Qd Sign of Slope Parameter P b = Qd/P is negative Inverse c = Qd/M is positive Direct for normal goods M c = Qd/M is negative Inverse for inferior goods d = Qd/PR is positive Direct for substitutes PR d = Qd/PR is negative Inverse for complements e = Qd/ is positive Direct Pe f = Qd/Pe is positive Direct N g = Qd/N is positive Direct
6
Demand Function Demand function, or demand, shows relation between P & Qd when all other variables are held constant Qd = f(P) Law of Demand Qd increases when P falls & Qd decreases when P rises, all else constant Qd/P must be negative
7
Graphing Demand Curves
Traditionally price (P) is plotted on the vertical axis & quantity demanded (Qd) is plotted on the horizontal axis The equation plotted is the inverse demand function P = f(Qd)
8
Graphing Demand Curves
A point on a 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
9
Graphing Demand Curves
Change in quantity demanded Occurs when price changes Movement along demand curve Change in demand Occurs when one of the other variables, or determinants of demand, changes Demand curve shifts rightward or leftward
10
Shifts in Demand (Figure 2.2)
Qd 1,100 700 100 Quantity Price (dollars) 900 P 300 500 1,500 1,300 10 20 30 40 50 60 70 80 D1 Demand increase D0 • $50, 300 $50, 600 • $40, 200 $40, 500 D2 Demand decrease
11
Supply Quantity supplied (Qs)
Amount of a good or service offered for sale during a given period of time
12
Supply Six variables that influence Qs Generalized supply function
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) Generalized supply function
13
Generalized Supply Function
k, l, m, n, r, & s are slope parameters Measure effect on Qs of changing one of the 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
14
Generalized Supply Function
Variable Relation to Qs Sign of Slope Parameter P k = Qs/P is positive Direct PI l = Qs/PI is negative Inverse m = Qs/Pr is negative Inverse for substitutes Pr m = Qs/Pr is positive Direct for complements T n = Qs/T is positive Direct Pe r = Qs/Pe is negative Inverse F s = Qs/F is positive Direct
15
Supply Function - thurs
Supply function, or supply, shows relation between P & Qs when all other variables are held constant Qs = g(P)
16
Graphing Supply Curves
A point on a supply curve shows either: Maximum amount of a good that will be offered for sale at a given price Minimum price necessary for producers to voluntarily offer a particular quantity for sale
17
Graphing Supply Curves
Change in quantity supplied Occurs when price changes Movement along supply curve Change in supply Occurs when one of the other variables, or determinants of supply, changes Supply curve shifts rightward or leftward
18
Shifts in Supply (Figure 2.4)
80 S0 70 Price (dollars) S1 $60, 700 $60, 400 • 60 Supply decrease 50 • $40, 500 $40, 650 40 Supply increase 30 20 10 Qs 100 300 500 700 900 Quantity
19
Market Equilibrium Equilibrium price & quantity are determined by the intersection of demand & supply curves At the point of intersection, Qd = Qs Consumers can purchase all they want & producers can sell all they want at the “market-clearing” price
20
Market Equilibrium (Figure 2.5)
P 80 S0 70 Price (dollars) D0 60 • 50 • 40 30 • 20 10 Qd , Qs 100 300 500 700 900 1,100 1,300 1,500 Quantity
21
Shortage When demand shifts outward, initially there will be what could be seen as a shortage of goods supplied at the original equilibrium price.
22
Demand Shifts (Supply Constant) (Figure 2.6)
80 D1 S0 70 Price (dollars) 60 • B 50 D2 A • • • 40 • C 30 20 10 D0 Qd , Qs 100 300 500 700 900 1,100 1,300 1,500 Quantity
23
Surplus When supply shifts out, it appears to be a surplus of goods at the old equilibrium price
24
Supply Shifts (Demand Constant) (Figure 2.7)
80 S1 S0 70 Price (dollars) 60 • T 50 R • • • 40 • S 30 20 10 D0 Qd , Qs 100 300 500 700 900 1,100 1,300 Quantity
25
Simultaneous Shifts When demand & supply shift simultaneously
Can predict either the direction in which price changes or the direction in which quantity changes, but not both The change in equilibrium price or quantity is said to be indeterminate when the direction of change depends on the relative magnitudes by which demand & supply shift
26
Simultaneous Shifts: (D, S)
P D’ S D S’ S’’ B • P’ A • Q’ P C • P’’ Q’’ Q Q Price may rise or fall; Quantity rises
27
Simultaneous Shifts: (D, S)
P S D S’ S’’ D’ A • P B • P’ Q’ C • P’’ Q’’ Q Q Price falls; Quantity may rise or fall
28
Simultaneous Shifts: (D, S)
P S’’ D’ S’ C • P’’ S D Q’’ B • P’ Q’ A • P Q Q Price rises; Quantity may rise or fall
29
Simultaneous Shifts: (D, S)
P S’’ S’ D S D’ C • P’’ • A P Q’’ B • P’ Q’ Q Q Price may rise or fall; Quantity falls
30
Ceiling & Floor Prices Ceiling price Floor price
Maximum price government allows sellers to charge for a good When ceiling price is below equilibrium, a shortage occurs Floor price Minimum price government allows sellers to charge for a good When floor price is above equilibrium, a surplus occurs
31
Ceiling & Floor Prices (Figure 2.11)
Px Px Price (dollars) Price (dollars) Sx Dx 2 50 Panel B – Floor price Sx 3 32 84 2 50 1 62 22 Dx Qx Qx Quantity Quantity Panel A – Ceiling price
32
Homework Read Chapter 2 Do Technical problems: 1, 2, 4, 6, 7, 9, 11, 12, 13, 14, 17 Do Applied Problems: 1, 2, 5, 11, 13, 14, Do Mathematical exercise : 2
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.