微观经济学—2(第二,三章).pptVIP

Units of Good X Units of Good X Units of good Y I1 I2 I3 I4 I5 I6 f B1 Income and substitution effects: normal good QX1 当X的价格上升时 Units of Good X Units of Good X Units of good Y I1 I2 I3 I4 I5 I6 f B1 QX1 h B2 QX3 Rise in the price of good X Income and substitution effects: normal good Units of Good X Units of Good X Units of good Y I1 I2 I3 I4 I5 I6 f B1 QX1 h B2 Substitution effect g QX2 B1a Substitution effect of the price rise Income and substitution effects: normal good 在一定的预算约束下，为了实现最大的效用，消费者应该选择的商品组合，要使得两商品的边际替代率等于两商品的价格之比。 *基数效用论和序数效用论的消费者均衡原则比较 需证明： Consumers would like to obtain the combination of goods on the highest possible indifference curve. However, the budget constraint may restrict or limit the consumer to a lower indifference curve. Combining the indifference curve and budget constraint determines the optimum choice. The Consumer’s Optimal Choice The point at which the indifference curve and the budget constraint touch (i.e. its tangent) is called the optimum. The consumer chooses consumption of the two goods so that the marginal rate of substitution equals the relative price. The consumer’s valuation of the two goods equals the market’s valuation. 第三节 价格变化和收入变化对消费者均衡的影响 一、价格变化 ： 1、价格－消费曲线 1、含义： 2、价格－消费曲线的形成 价格-消费曲线是在消费者的偏好、收入以及其他商品价格不变的条件下，与某一种商品的不同价格相联系的消费者效用最大化的均衡点的轨迹。 Units of good Y Units of good X Assumptions PX = ￡2 PY = ￡1 Budget = ￡30 B1 I1 j Effect of a fall in the price of good X Units of good Y Units of good X Assumptions PX = ￡1 PY = ￡1 Budget = ￡30 B1 I1 j I2 B2 k a Effect of a fall in the price of good X Units of good Y Units of good X B1 I1 j I2 B2 k Price–consumption curve a Effect of a fall in the price of good X 2、消费者的需求曲线 1、推导：每一个均衡点上商品x的价格和商品x的需求量之间有一一对应关系，将该关系绘制在商品的价格－数量坐标图上，便可得到单个消费者的需求曲线。 2、特征：向右下方倾斜，需求曲线上与每一价格水平相对应的水平需求量都是可以给消费者带来最大效用的均衡数量。 B1 I1 Expenditure on all other goods Units of good X a Deriving a demand curve from a price–consumption curve I2 B1 B2 I1 Expenditure on all other goods Units