《10理性消费者PPT课件》由会员分享，可在线阅读，更多相关《10理性消费者PPT课件（22页珍藏版）》请在金锄头文库上搜索。
1、WHAT YOU WILL LEARN IN THIS CHAPTERchapter: 10Krugman/WellsEconomics2009 Worth PublishersThe Rational ConsumerHow consumers choose to spend their income on goods and servicesWhy consumers make choices by maximizing utility, a measure of satisfaction from consumptionWhy the principle of diminishing m
2、arginal utility applies to the consumption of most goods and servicesHow to use marginal analysis to find the optimal consumption bundleWhat income and substitution effects areOpportunity Cost and DecisionsThe utility of a consumer is a measure of the satisfaction the consumer derives from consumpti
3、on of goods and services.An individuals consumption bundle is the collection of all the goods and services consumed by that individual.An individuals utility function gives the total utility generated by his or her consumption bundle. The unit of utility is a util.1513119753110152839485560636463Tota
4、l utility (utils)Marginal utility per clam (utils)0123456789Quantity of clamsUtility functionMarginal Utility Curve798654321070605040302010Total utility (utils)Quantity of clams79865432116141210864202Marginal utility per clams (utils)Quantity of clams(a)Cassies Utility Function(b)Cassies Marginal Ut
5、ility CurveCassies Total Utility and Marginal UtilityCassies Total Utility and Marginal UtilityCassies total utility depends on her consumption of fried clams. It increases until it reaches its maximum utility level of 64 utils at 8 clams consumed and decreases after that.The marginal utility curve
6、slopes downward due to diminishing marginal utility; each additional clam gives Cassie less utility than the previous clam.The Principle of Diminishing Marginal UtilityThe marginal utility of a good or service is the change in total utility generated by consuming one additional unit of that good or
7、service. The marginal utility curve shows how marginal utility depends on the quantity of a good or service consumed.The principle of diminishing marginal utility says that each successive unit of a good or service consumed adds less to total utility than the previous unit.Budgets and Optimal Consum
8、ptionA budget constraint requires that the cost of a consumers consumption bundle be no more than the consumers total income.A consumers consumption possibilities is the set of all consumption bundles that can be consumed given the consumers income and prevailing prices.A consumers budget line shows
9、 the consumption bundles available to a consumer who spends all of his or her income.102345108642ABCDEFAffordable consumption bundles that cost all of Sammys incomeSammys Budget Line, BLAffordable consumption bundlesUnaffordable consumption bundlesQuantity of clams (pounds)Quantity of potatoes (poun
10、ds)ABCDEFConsumption bundle012345Quantity of clams(pounds)1086420Quantity of potatoes(pounds)The Budget LineSammys Utility from ConsumptionOptimal Consumption ChoiceThe optimal consumption bundle is the consumption bundle that maximizes a consumers total utility given his or her budget constraint.Sa
11、mmys Budget and Total UtilitySammys total utility is the sum of the utility he gets from clams and the utility he gets from potatoes.Quantity of potatoes (pounds)543210108642AABBCCDDEEBLUtility functionFF5432108070605040302010Quantity of clams (pounds)0246810(a) Sammys Budget Line(b) Sammys Utility
12、FunctionThe optimal consumption bundleQuantity of clams (pounds)Quantity of potatoes (pounds) maximizes total utility given the budget constraintTotal utility (utils)Optimal Consumption BundleSammys total utility is maximized at bundle C, where he consumes 2 pounds of clams and 6 pounds of potatoes.
13、 This is Sammys optimal consumption bundle.Spending the Marginal DollarThe marginal utility per dollar spent on a good or service is the additional utility from spending one more dollar on that good or service.Sammys Marginal Utility per DollarMarginal Utility per DollarIf Sammy has, in fact, chosen
14、 his optimal consumption bundle, his marginal utility per dollar spent on clams and potatoes must be equal.654321BCBPMUC/PCMUP/PPC5432100246810Total utility (utils)Quantity of clams (pounds)Quantity of potatoes (pounds)At the optimal consumption bundle, the marginal utility per dollar spent on clams
15、 is equal to the marginal utility per dollar spent on potatoes.Optimal Consumption RuleThe optimal consumption rule says that when a consumer maximizes utility, the marginal utility per dollar spent must be the same for all goods and services in the consumption bundle.From Utility to the Demand Curv
16、eThe main reason for studying consumer behavior is to understand how the downward slope of the market demand curve is explained by the utility-maximizing behavior of individual consumers.Marginal Utility, the Substitution Effect, and the Law of DemandThe substitution effect of a change in the price
17、of a good is the change in the quantity consumed of that good as the consumer substitutes the good that has become relatively cheaper for the good that has become relatively more expensive.The Income EffectThe income effect of a change in the price of a good is the change in the quantity consumed of
18、 that good that results from a change in the consumers purchasing power due to the change in the price of the good.Normal GoodsInferior GoodsGiffen GoodsSUMMARY1.Consumers maximize a measure of satisfaction called utility. Each consumer has a utility function that determines the level of total utili
19、ty generated by his or her consumption bundle, the goods and services that are consumed.2.A goods or services marginal utility is the additional utility generated by consuming one more unit of the good or service. We usually assume that the principle of diminishing marginal utility holds: consumptio
20、n of another unit of a good or service yields less additional utility than the previous unit.SUMMARY3.A budget constraint limits a consumers spending to no more than his or her income. It defines the consumers consumption possibilities, the set of all affordable consumption bundles. A consumer who s
21、pends all of his or her income will choose a consumption bundle on the budget line. An individual chooses the consumption bundle that maximizes total utility, the optimal consumption bundle.4.The optimal consumption rule says that at the optimal consumption bundle the marginal utility per dollar spe
22、nt on each good and service is the same.SUMMARY5.Changes in the price of a good affect the quantity consumed in two possible ways: the substitution effect and the income effect. For normal goods, the substitution and income effects reinforce each other. For inferior goods, however, they work in opposite directions.
