《微观经济学》平狄克 第4章个人需求和市场需求.ppt

1 4 4 4 4 4 4 4 4 4 4 4 Positive NetworkExternality: Bandwagon Effect Chapter 4 Slide * Demand Quantity (thousands per month) Price ($ per unit) D20 20 40 60 80 100 D40 D60 D80 D100 The market demand curve is found by joining the points on the individual demand curves. It is relatively more elastic. Positive NetworkExternality: Bandwagon Effect Chapter 4 Slide * Demand Quantity (thousands per month) Price ($ per unit) D20 20 40 60 80 100 D40 D60 D80 D100 Pure Price Effect 48 Suppose the price falls from $30 to $20. If there were no bandwagon effect, quantity demanded would only increase to 48,000 $20 $30 Positive NetworkExternality: Bandwagon Effect Chapter 4 Slide * Demand Quantity (thousands per month) Price ($ per unit) D20 20 40 60 80 100 D40 D60 D80 D100 Pure Price Effect $20 48 Bandwagon Effect But as more people buy the good, it becomes stylish to own it and the quantity demanded increases further. $30 Network Externalities The Snob Effect If the network externality is negative, a snob effect exists. The snob effect refers to the desire to own exclusive or unique goods. The quantity demanded of a “snob” good is higher the fewer the people who own it. Chapter 4 Slide * Negative NetworkExternality: Snob Effect Chapter 4 Slide * Quantity (thousands per month) Price ($ per unit) Demand 2 D2 $30,000 $15,000 14 Pure Price Effect Originally demand is D2, when consumers think 2000 people have bought a good. 4 6 8 D4 D6 D8 However, if consumers think 4,000 people have bought the good, demand shifts from D2 to D6 and its snob value has been reduced. Negative NetworkExternality: Snob Effect Chapter 4 Slide * Quantity (thousands per month) 2 4 6 8 The demand is less elastic and as a snob good its value is greatly reduced if more people own it. Sales decrease as a result. Examples: Rolex watches and long lines at the ski lift. Price ($ per unit) D2 $30,000 $15,000 14 D4 D6 D8 Demand Pure Price Effect Snob Effect Net Effect Network Externalitie