管理经济学托马斯版Chap005

• Nonsatiation
• More of a good is always preferred to less
5-5
Utility
• Benefits consumers obtain from goods & services they consume is utility
• A utility function shows an individual’s perception of the utility level attained from consuming each conceivable bundle of goods
MUX MUY
PX
PY
5-18
Constrained Utility Maximization
(Figure 5.8)
• Negative of the slope of the indifference curve • Diminishes along the indifference curve as X
increases & Y decreases • Ratio of the marginal utilities of the goods
Indifference Map (Figure 5.4)
IV III II I
Quantity of X
5-11
Marginal Utility
• Addition to total utility attributable to the addition of one unit of a good to the current rate of consumption, holding constant the amounts of all other goods consumed
5-13
Consumer’s Budget Constraint
(Figure 5.5)
5-14
Typical Budget Line (Figure 5.6)
• M A
PY Y M PX X PY PY
Quantity of Y
Quantity of X
•B
M
PX
5-15
Shifting Budget Lines (Figure 5.7)
5-6
Indifference Curves
• Locus of points representing different bundles of goods, each of which yields the same level of total utility
• Negatively sloped & convex
MRSYMUX X MUY
5-9
Slope of an Indifference Curve & the MRS (Figure 5.3)
Quantity of good Y
A 600 320
0
T C (360,320)
I T’
B
360
800
Quantity of good X
5-10
Quantity of Y
5-16
Utility Maximization
• Utility maximization subject to a limited money income occurs at the combination of goods for which the indifference curve is just tangent to the budget line
5-7
Typical Indifference Curve
(Figure 5.2)
5-8
Marginal Rate of Substitution
• MRS shows the rate at which one good can be substituted for another while keeping utility constant
Quantity of Y Quantity of Y
120 R 100 A
80 F
ZB N 160 200 240
Quantity of X
Panel A – Changes in money income
A 100
C
B
பைடு நூலகம்
D
125
200
250
Quantity of X
Panel B – Changes in price of X
A is preferred to B B is preferred to A The consumer is indifferent between A and B
• Transitivity
• If A is preferred to B, and B is preferred to C, then A must be preferred to C
MUUX
5-12
Consumer’s Budget Line
• Shows all possible commodity bundles that can be purchased at given prices with a fixed money income
MPXXPYY
or
Y M PX X PY PY
M RSYM UXPX X M UY PY
5-17
Utility Maximization
• Consumer allocates income so that the marginal utility per dollar spent on each good is the same for all commodities purchased
管理经济学托马斯版Chap005
5-2
5-3
Typical Consumption Bundles for Two Goods, X & Y (Figure 5.1)
5-4
Properties of Consumer Preferences
• Completeness
• For every pair of consumption bundles, A and B, the consumer can say one of the following: