111 厂商利润最大化的选择.PPTVIP

* * * * * * * * * * * * * * * * * * * * * * * * * 11.3 長期的產量、價格與利潤 廠商採用新技術並賺取經濟利潤 使用新技術的廠商刺激了其他進入者 使用舊技術的廠商遭受經濟損失 這些廠商要不退出市場，就是跟進採用新技術 11.3 長期的產量、價格與利潤 完全競爭是否有效率？ 完全競爭是有效率的市場型態 廠商的供給曲線是邊際成本曲線在平均變動成本最低點以上的部分，市場供給曲線是廠商供給曲線的水平加總 市場供給曲線為整個產業的邊際成本曲線 (圖 11.13 說明完全競爭的效率) 11.3 長期的產量、價格與利潤 1. 市場均衡為價格等於$5/罐，數量為 90罐/天 供給曲線同時為邊際成本 曲線 需求曲線同時為邊際利益曲線 圖 11.13 完全競爭的效率 11.3 長期的產量、價格與利潤 因為邊際利益等於邊際成本 生產的數量為效率數量 總剩餘 (消費者剩餘加生產者剩餘) 達到最大 * * * Launch your lecture by drawing a spectrum of market types noting the four market structures to be studied in this and the next chapters. Let your students know that you will be comparing how a firm in each of these market structures chooses its equilibrium price and equilibrium quantity. Putting this diagram on the board provides a good perspective for the following chapters. * * * Once you discuss the characteristics that define perfect competition (many firms selling an identical product to many buyers, no restrictions on entry, established firms have no cost advantage over new firms, and sellers and buyers are well informed about prices) it is natural to give examples of perfectly competitive markets. The examples that always spring to mind are agricultural in nature. Often students, particularly those in urban areas, wonder why they will spend so much of their time studying agriculture. You need to combat the natural view that the model of perfect competition applies only to farms. There are two, complementary paths you can take: First, tell your students that although agriculture certainly meets all the requirements of perfect competition, a lot of other industries come close. If you have a mall near by, you can assign your students to walk through the mall and take note of the different types of businesses and list those that they think are closest to perfect competition. Businesses such as shoe stores, jewelry, toy stores, book stores, hair salons, and so forth are all commonly found in malls and are all relatively close to being in pe