sahid university managerial economics ch4 the theory of individual behavior
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Sahid University Managerial Economics Ch4 the Theory of Individual BehaviorTRANSCRIPT
Ch 4. The Theory of Ch 4. The Theory of Individual BehaviorIndividual Behavior
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Consumer BehaviorConsumer BehaviorAssume 2 goods exist in the
economy.
Assume a consumer is able to order his or her preferences for alternative bundles or combinations of goods from best to worst.
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Consumer BehaviorConsumer BehaviorA > B the consumer prefers bundle A
to bundle B.
A – B the consumers view the two
bundles as equally satisfying. He or she indifferent between bundles A and B.
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Consumer BehaviorConsumer BehaviorThe preference ordering is The preference ordering is
assumed to satisfy four basic assumed to satisfy four basic properties:properties:
1. Completeness. 2. More is better. 3. Diminishing marginal rate of substitution. 4. Transitivity.
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Consumer BehaviorConsumer BehaviorCompleteness:Completeness: - for any two bundles, say A and
B, either A > B, B > A, A – B.
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Consumer BehaviorConsumer BehaviorMore is better:More is better: - for any two bundles, say A and
B, either A > B, B > A, A – B.
Figure 4-1 Page 120.
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Consumer BehaviorConsumer BehaviorDiminishing marginal rate of Diminishing marginal rate of
substitution:substitution: - As a consumer obtains more of
good X, the rate at which he or she is willing to substitute good X for
good Y decreases.
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Consumer BehaviorConsumer BehaviorTransitivity:Transitivity: - For any three bundles, A, B,
and C, if A > B and B > C, then A > C. Similarly A – B, and B – C, then
A - C
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The Budget ConstraintThe Budget ConstraintBudget set:Budget set: The bundles of goods a
consumer can afford.
Px X + Py Y equals or less M
The budget set.
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The Budget ConstraintThe Budget ConstraintBudget line:Budget line: The bundles of goods that
exhaust a consumer’s income.
Px X + Py Y = M
The budget line.
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Changes In IncomeChanges In IncomeChanges in income shrink or
expand opportunities.
Figure 4-5 Page 126.
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Changes In PricesChanges In PricesFigure 4-6 Page 127.
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Consumer EquilibriumConsumer EquilibriumThe objective of the consumer is to
choose the consumption bundle that maximizes his or her utility, or satisfaction.
Consumer equilibrium:Consumer equilibrium: The affordable bundle that yields
the greatest satisfaction to the consumer.
Figure 4-8 Page 128.13
Consumer EquilibriumConsumer Equilibrium
Consumer equilibrium:Consumer equilibrium: MRS = (Px / Py) MRS = marginal rate of
substitution Px = price of good X Py = price of good Y
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Comparative StaticsComparative Statics(Price Changes and Consumer Behavior)(Price Changes and Consumer Behavior)
A change in the price of a good will lead to a change in the equilibrium consumption bundle.
Figure 4-9 Page 130. Change in consumer equilibrium
due to a decrease in the price of good X (Note: that good Y is a substitute for good X).
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Comparative StaticsComparative Statics(Price Changes and Consumer Behavior)(Price Changes and Consumer Behavior)
Figure 4-10 Page 131. When the price of good X falls,
the consumption of complementary good Y rises.
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Comparative StaticsComparative Statics(Income Changes and Consumer (Income Changes and Consumer Behavior)Behavior)
Figure 4-11 Page 132. An increase in income increases
the consumption of normal goods.
Figure 4-12 Page 133. An increase in income decreases
the equilibrium consumption of good X (an inferior good).
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Conceptual and Conceptual and Computational QuestionsComputational Questions1. A consumer has $400 to spend on goods X and Y. The market prices of these two
goods are Px = $10 and Py = $40. 1.a. Illustrate the consumer’s opportunity set in a carefully labeled diagram. 1.b. Show how the consumer’s opportunity set changes if income increases by $400. How does the $400 increases in income alter the market rate of substitution between goods X and Y?
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Conceptual and Conceptual and Computational QuestionsComputational Questions2. A consumer must divide $250 between the
consumption of product X and product Y. The relevant market prices are Px=$5 and Py=$10.
2.a. Write the equation for the consumer’s budget line. 2.b. Illustrate the consumer’s opportunity set
in a carefully labeled diagram. 2.c. Show how the consumer’s opportunity set
changes when the price of good X
increases to $10?
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Conceptual and Conceptual and Computational QuestionsComputational Questions3. A consumer is in equilibrium at point A in the
accompanying figure (Figure at page 148). The price of good X is $5.
3.a. What is the price of good Y?
3.b. What is the consumer’s income?
3.c. At point A, how many units of good X does
the consumer purchase?
3.d. Suppose the budget line changes so that the
consumer achieves a new equilibrium at
point B. What change in the economic
environment led to this new equilibrium? Is
the consumer better off or worse off as a
result of the price change?
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