帕金经济学第9版课件Ch08-9e-lecture

The utility-maximizing combination is called a consumer equilibrium.
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Maximizing Utility
Table 8.2 shows Lisa’s utilitymaximizing choice. Lisa has $40 a month to spend on movies and soda. The price of a movie is $8 and the price of soda is $4 a case.
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Maximizing Utility
Figure 8.1(a) shows a total utility curve for soda. Total utility increases with the consumption of a soda increases.
Lisa gets 90 units of utility from the 2 movies and 225 units of utility from the 6 cases of soda.
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Maximizing Utility
Choosing at the Margin
Maximizing Utility
Table 8.1 provides an example of total utility schedule. Total utility from a good increases as the quantity of the good increases. For example, as the number of movies seen in a month increases, total utility from movies increases.
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Maximizing Utility
Preferences A household’s preferences determine the benefits or satisfaction a person receives consuming a good or service. The benefit or satisfaction from consuming a good or service is called utility.
Or will you buy the album on a CD and download the single?
What determines our choices as buyers of recorded music? You know that diamonds are expensive and water is cheap. Doesn’t that seem odd? Why do we place a higher value on useless diamonds than on essential-to-life water?
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Maximizing Utility
The key assumption of marginal utility theory is that the household chooses the consumption possibility that maximizes total utility. The Utility-Maximizing Choice We can find the utility-maximizing choice by looking at the total utility that arises from each affordable combination.
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Maximizing Utility
Total utility is maximized when:
MUM/PM = MUS/PS
Table 8.3 shows why the utility-maximizing rule works.
The combination is each row is affordable (costs $40). In row C, MUM/PM = MUS/PS = 5.
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Predictions of Marginal Utility Theory
A Fall in the Price of a Movie When the price of a good falls the quantity demanded of that good increases—the demand curve slopes downward.
Total Utility
Total utility is the total benefit a person gets from the consumption of goods. Generally, more consumption gives more utility.
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Maximizing Utility
If MUS/PS > MUM/PM, then spend more on soda and less on movies.
MUS decreases and
MUM increases. Only when MUM/PM = MUS/PS, is it not possible to reallocate the budget and increase total utility.
A consumer’s total utility is maximized by following the rule:
Spend all available income.
Equalize the marginal utility per dollar for all goods. The marginal utility per dollar is the marginal utility from a good divided by its price.
Each row of the table shows a combination of movies and soda that exhausts Lisa’s $40.
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Maximizing Utility
Lisa chooses the combination that gives her the highest total utility. Lisa maximizes her total utility when she sees 2 movies and drinks 6 cases of soda a month.
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Maximizing Utility
Figure 8.1(b) illustrates diminishing marginal utility.
As the quantity of soda increases, the marginal utility from soda diminishes.
We call this decrease in marginal utility as the quantity of the good consumed increases the principle of diminishing marginal utility.
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Maximizing Utility
Table 8.1 provides an example of marginal utility schedule. Marginal utility from a good decreases as the quantity of the good increases. For example, as the number of movies seen in a month increases, marginal utility from movies decreasson Education
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You want Coldplay’s latest hit album, Viva la Vida, and you want the Justin Timberlake and Madonna single, Four Minutes. Will you download the album and the single? Or will you buy two CDs?
For example, if the price of a movie falls, we know that MUM/PM rises, so before the consumer changes the quantities bought, MUM/PM > MUS/PS. To restore consumer equilibrium (maximum total utility) the consumer increases the movies seen to drive down the MUM and restore MUM/PM = MUS/PS.
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Maximizing Utility
Marginal Utility Marginal utility is the change in total utility that results from a one-unit increase in the quantity of a good consumed. As the quantity consumed of a good increases, the marginal utility from consuming it decreases.
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Maximizing Utility
The Utility-Maximizing Rule: Call the marginal utility of movies MUM . Call the marginal utility of soda MUS . Call the price of movies PM . Call the price of soda PS . The marginal utility per dollar from seeing movies is MUM/PM . The marginal utility per dollar from soda is MUS/PS.
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Maximizing Utility
If MUM/PM > MUS/PS,
then spend less on soda and more on movies.
MUM decreases and
MUS increases. Only when MUM/PM = MUS/PS, is it not possible to reallocate the budget and increase total utility.