宏观经济学第导言.pptVIP

1.2.1一个简单的经济模型: 轿车的供给与需求 解释轿车销售价格与销售量的决定因素。 假定市场是竞争的：即每个买者与卖者的市场份额都是非常的小，不足以影响市场价格 变量： Q d =消费者的需求量 Q s =厂商的供应量 P = 轿车的价格 Y =总收入 Ps = 钢材价格（是一种投入） 轿车需求模型：用数学方程表示 表明消费者的轿车需求量 与轿车的销售价格以及 总收入相关。  题外话：函数注释 一般函数关系式仅表明以下变量是相关的： 对需求量有影响的一系列变量 题外话：函数注释 一般函数关系式仅表明以下变量是相关的： 具体的函数形式可用以表明变量间的精确的数量关系 例如： 新轿车的市场需求 Q 轿车需求量 P 轿车 价格 D（？） 需求曲线： 在其它因素不变时，需求曲线表明了需求量与价格间的关系。 需求方程： 新轿车的市场供应 Q 轿车 需求量 P 轿车 价格 D S（？） 供给曲线： 在其它因素不变的情况下，供给曲线反映了供给量与价格间的关系。 供需模型的应用之一：市场均衡分析 Q 轿车 数量 P 轿车 价格 S D 均衡价格 均衡数量 第一章：宏观经济学概述 slide * 宏观经济学 第五版 N.G 曼昆 教学幻灯片  制作： Ron Cronovich 第一章 宏观经济学概述 macro ? 2002 Worth Publishers, all rights reserved * This graph shows data on U.S. Gross Domestic Product. For now, it suffices for students to know that GDP is a measure of the economy’s total output and total income, and that the data in this chart have been adjusted to take out the effects of inflation. (In Chapter 2, students will learn the exact definition of GDP, how it’s measured, and how it’s corrected for inflation). There are two main points students should get from this graph. First, over the long run, there’s a clear upward trend. One of the most important issues in macroeconomics is understanding this long run growth: what determines how fast a country grows over the long run, how do government policies affect the growth rate, and how could we achieve faster growth? This topic is critical, because it’s very tightly linked to our standard of living. (continued next slide….) * Second, the economy doesn’t always grow smoothly: over the short run, the economy sometimes experiences periods of falling GDP, called recessions. What students see in this graph as little downward blips correspond to periods during which hundreds of thousands of workers lose their jobs. Periods of rising GDP are called “expansions.” In March 2001, the U.S. completed the longest expansion on record. When the economy is expanding, firms are producing more goods and services, and therefore hir