经济学基础第四课(曼昆第六版)讲解.ppt

内容提要 为了分析某个事件如何影响一个市场，我们用供求图来考察该事件对均衡价格和均衡数量的影响。我们遵循三个步骤进行：第一，确定该事件是使供给曲线移动，还是使需求曲线移动（还是使两者都移动）。第二，确定曲线移动的方向。第三，比较新均衡与原来的均衡 在市场经济中，价格是引导经济决策，从而配置稀缺资源的信号 * This is perhaps the most important chapter in the textbook. It’s worth mentioning to your students that investing extra time to master this chapter will make it easier for them to learn much of the subsequent material in the book. This is also one of the longest chapters in the textbook, and this PowerPoint file is one of the most graph-intensive. Many students taking economics for the first time have difficulty grasping the graphs, which are critically important in this and all subsequent chapters in the book. So an extra degree of hand-holding might be appropriate. Accordingly, this PowerPoint has carefully detailed animations that build many of the graphs with great care. For example, we show a demand or supply schedule next to the axes, and highlight each coordinate pair in the table as the corresponding point appears on the graph. Please be assured that the presentation of graphs is more streamlined in subsequent chapters. In this early chapter, though, we do not want to leave any students behind. If your students are already very comfortable with scatter-type graphs, you may wish to simplify or turn off the animation on these slides, in order to get through them faster. * In the real world, there are relatively few perfectly competitive markets. Most goods come in lots of different varieties – including ice cream, the example in the textbook. And there are many markets in which the number of firms is small enough that some of them have the ability to affect the market price. For now, though, we look at supply and demand in perfectly competitive markets, for two reasons: First, it’s easier to learn. Understanding perfectly competitive markets makes it a lot easier to learn the more realistic but complicated analysis of imperfectly competitive markets. Second, despite the lack of reali