1 00:00:00,000 --> 00:00:03,481 ♪ [音乐] ♪ 2 00:00:09,090 --> 00:00:12,560 -[亚历克斯]在竞争市场中, 我们知道价格等于边际成本 3 00:00:12,740 --> 00:00:16,970 在垄断市场中 我们知道价格会比边际成本高 4 00:00:17,150 --> 00:00:23,300 但会高多少呢? 是什么决定了利润? 5 00:00:23,480 --> 00:00:27,760 我们今天这节课要讨论 垄断的利润决定与需求弹性 6 00:00:27,940 --> 00:00:37,530 让我们简要回顾一下上一节课 7 00:00:37,710 --> 00:00:42,180 大家都应该很熟悉这张图表了 8 00:00:42,360 --> 00:00:46,040 我们知道如何找到边际收益曲线 曲线由垂直虚线出发 9 00:00:46,220 --> 00:00:49,850 与需求曲线同一点出发, 但有两倍的斜率 10 00:00:50,030 --> 00:00:54,150 我们知道在当边际收益与边际成本相等时 收益最大化 11 00:00:54,330 --> 00:00:58,960 并且我们知道收益最大化时的价格 是人们愿意购买这些数目商品的最高价格 12 00:00:59,140 --> 00:01:04,090 在这个例子里,是$12.50 13 00:01:04,269 --> 00:01:09,740 垄断利润是边际啊成本和价格的差别 14 00:01:09,920 --> 00:01:14,290 我们知道在一个竞争性市场中 价格会等于边际成本 15 00:01:14,470 --> 00:01:19,420 而我们这里的平衡点, 价格远高于边际成本,这就是垄断利润 16 00:01:19,600 --> 00:01:25,000 我们开可以读这个图 垄断者的利润要比普通利润高 17 00:01:25,180 --> 00:01:29,800 利润是价格和平均成本的差别乘以数量 18 00:01:29,980 --> 00:01:34,920 也就是途中的阴影部分 好了,这就是上节课的回顾 19 00:01:35,100 --> 00:01:43,990 现在让我们用直觉猜测 是什么决定了垄断利润 20 00:01:44,170 --> 00:01:48,470 让我们用药企的例子 有两个因素提高了垄断利润 21 00:01:48,650 --> 00:01:54,320 第一个 “你不能没有他”效应 22 00:01:54,500 --> 00:01:59,660 重病的人会对救命的药的 价格敏感度变低 23 00:01:59,840 --> 00:02:04,220 你没了它就活不了 所以你会倾尽所有来拯救你的生命 24 00:02:04,400 --> 00:02:08,300 如果救命药的价格上涨 25 00:02:08,479 --> 00:02:16,160 他的需求并不会降低很多 26 00:02:16,340 --> 00:02:19,750 因为消费者对它的价格不敏感 垄断者会说 27 00:02:19,930 --> 00:02:24,460 “我可以涨价,他们还是会买 因此我可以涨价 28 00:02:24,640 --> 00:02:30,060 涨价可以让我的利益最大化。” 29 00:02:30,240 --> 00:02:35,390 另外一个效应是 “这是别人的钱”效应 30 00:02:35,570 --> 00:02:38,660 如果别人付医药费 消费者会降低对价格的敏感度 31 00:02:38,840 --> 00:02:42,880 我们知道在制药业 通常是保险公司,医保或政府项目 32 00:02:43,060 --> 00:02:46,670 会支付医药费 33 00:02:46,850 --> 00:02:50,980 因此需要药的人 并不会支付费用 34 00:02:51,160 --> 00:02:55,300 所以及时价格上涨 他们还是会买 35 00:02:55,480 --> 00:03:01,570 需求量不会降低太多 因此我们在这的结论是 36 00:03:01,750 --> 00:03:08,000 消费者对价格的敏感度越低 垄断的利润越高 37 00:03:08,180 --> 00:03:12,030 如果人们对价格完全不敏感 垄断者会说 38 00:03:12,210 --> 00:03:18,590 “太好了,我可以抬高价格 并保持之前的销量。“ 39 00:03:18,770 --> 00:03:25,890 换句话说需求曲线的弹性越低 利润越高。这是基本点 40 00:03:26,070 --> 00:03:30,100 现在我们有了知觉 让我们需求曲线图表测试它 41 00:03:30,280 --> 00:03:34,320 我们有两条需求曲线。 那一条更有弹性?左边的还是右边的? 42 00:03:34,500 --> 00:03:43,100 在左边的需求曲线更有弹性 右边的需求曲线弹性较低 43 00:03:43,280 --> 00:03:49,690 因此凭借我们的直觉 我们可以预期左边有较低利润 44 00:03:49,870 --> 00:03:55,860 而右边有较高利润,我们知道 如何找到利润最大化的价格和产量 45 00:03:56,040 --> 00:04:00,730 让我们做一下 首先,从左边开始 46 00:04:00,910 --> 00:04:06,390 我们可以看见,当需求曲线的弹性较高时 想对边际成本,我们的利润较低 47 00:04:06,570 --> 00:04:13,200 那右边的呢? 48 00:04:13,380 --> 00:04:19,079 我们又一条相对弹性低的需求曲线 我们可以看到价格远高于边际成本 49 00:04:19,260 --> 00:04:25,040 我们有一个相对弹性低的需求 我们可以抬高价格 50 00:04:25,220 --> 00:04:32,230 请注意这两个市场的边际成本是相同的 51 00:04:32,410 --> 00:04:38,220 区别就在于有变的需求曲线弹性较低 记住这个逻辑 52 00:04:38,400 --> 00:04:44,740 当垄断者发现顾客对价格不敏感时 53 00:04:44,920 --> 00:04:50,780 那他就知道如果价格上涨 需求量仅会降低一点点 54 00:04:50,960 --> 00:04:55,500 因此,抬高价格可议提高垄断者的收益 55 00:04:55,680 --> 00:05:00,290 56 00:05:00,470 --> 00:05:07,270 57 00:05:07,450 --> 00:05:13,740 58 00:05:13,920 --> 00:05:19,310 59 00:05:19,490 --> 00:05:23,530 60 00:05:23,710 --> 00:05:29,270 61 00:05:29,450 --> 00:05:35,040 62 00:05:35,220 --> 00:05:41,510 63 00:05:41,690 --> 00:05:45,960 64 00:05:46,140 --> 00:05:52,270 65 00:05:52,450 --> 00:05:58,190 66 00:05:58,370 --> 00:06:01,970 67 00:06:02,150 --> 00:06:07,760 68 00:06:07,940 --> 00:06:10,760 69 00:06:10,940 --> 00:06:15,690 70 00:06:15,870 --> 00:06:20,990 71 00:06:21,170 --> 00:06:25,660 72 00:06:25,840 --> 00:06:33,040 73 00:06:33,220 --> 00:06:39,050 74 00:06:39,230 --> 00:06:45,550 75 00:06:45,730 --> 00:06:52,610 76 00:06:52,790 --> 00:06:57,400 77 00:06:57,580 --> 00:07:02,590 78 00:07:02,770 --> 00:07:07,210 79 00:07:07,390 --> 00:07:13,150 80 00:07:13,330 --> 00:07:17,990 81 00:07:18,170 --> 00:07:23,080 82 00:07:23,260 --> 00:07:27,150 83 00:07:27,330 --> 00:07:32,900 84 00:07:33,080 --> 00:07:38,470 85 00:07:38,650 --> 00:07:46,640 86 00:07:46,820 --> 00:07:52,060 87 00:07:52,240 --> 00:07:57,590 88 00:07:57,770 --> 00:08:01,750 89 00:08:01,930 --> 00:08:05,980 90 00:08:06,160 --> 00:08:12,660 91 00:08:12,840 --> 00:08:17,620 92 00:08:17,800 --> 00:08:22,720 93 00:08:22,900 --> 00:08:28,740 94 00:08:28,920 --> 00:08:35,690 95 00:08:35,870 --> 00:08:39,147 96 00:08:39,147 --> 00:08:41,719 97 00:08:41,719 --> 00:08:46,790 - [广播]如果你想要测试自己 请点击“练习题” 98 00:08:46,970 --> 00:08:50,525 如果你准备好上下一课 请点击“下一个视频”