WEBVTT 00:00:00.000 --> 00:00:02.550 ♪ [音乐] ♪ 00:00:03.800 --> 00:00:05.800 - [旁白] 欢迎收看“诺奖得主畅谈系列” 00:00:07.040 --> 00:00:08.100 在这一集中 00:00:08.100 --> 00:00:11.570 Josh Angrist 和 Guido Imbens 与 Isaiah Andrews 00:00:11.570 --> 00:00:14.600 将讨论计量经济学领域是如何发展的 00:00:16.100 --> 00:00:18.750 - [Isaiah] 那么,Guido 和 Josh 00:00:18.750 --> 00:00:21.500 你们都是开发经济学实证研究工具的先驱 00:00:21.500 --> 00:00:23.174 所以我想了解你对这个领域的发展方向的想法 00:00:23.174 --> 00:00:25.300 00:00:25.709 --> 00:00:28.079 经济学、计量经济学,整个领域 00:00:28.510 --> 00:00:31.302 首先,我很想听听你是否觉得 00:00:32.171 --> 00:00:35.200 局部平均处理效应框架的方式 00:00:35.200 --> 00:00:38.510 00:00:38.800 --> 00:00:42.187 对经济学中的新经验法如何发展和传播 00:00:42.187 --> 00:00:44.300 或它们应如何发展和传播有任何榜样 00:00:44.560 --> 00:00:45.960 - [Josh] 这是个好问题 00:00:46.610 --> 00:00:47.790 你先说吧 00:00:47.790 --> 00:00:49.240 [笑声] 00:00:49.700 --> 00:00:52.940 - [Guido] 是的,所以我认为重要的是 00:00:52.940 --> 00:00:58.550 要提出令人信服的案例 00:00:58.550 --> 00:01:02.207 其中问题清晰 00:01:02.400 --> 00:01:05.720 且方法普遍适用 00:01:06.253 --> 00:01:07.560 有一件事我... 00:01:08.192 --> 00:01:12.000 当我回顾较新的文献时 00:01:12.200 --> 00:01:16.700 我真的很喜欢回归不连续性文献 00:01:16.700 --> 00:01:19.670 其中显然有一堆非常有说服力的例子 00:01:19.670 --> 00:01:23.378 这让人们可以更清晰地思考 00:01:23.378 --> 00:01:27.200 更仔细地研究方法问题 00:01:27.400 --> 00:01:28.800 有着一些清晰的应用方法 00:01:28.800 --> 00:01:30.600 然后允许你思考: 00:01:30.600 --> 00:01:33.600 “哇,这些类型的假设在这里看起来合理吗? 00:01:33.600 --> 00:01:38.000 我们不喜欢早期论文中的哪些方面? 00:01:38.500 --> 00:01:39.802 我们如何改进这些方面?” 00:01:39.802 --> 00:01:44.210 因此,我认为有着明确的应用方法 00:01:44.210 --> 00:01:46.400 来激发这些文献是非常有帮助的 00:01:46.800 --> 00:01:48.050 - Guido,我很高兴 你提到了回归不连续性 00:01:48.050 --> 00:01:49.382 00:01:49.382 --> 00:01:53.300 我认为 IV 和 RD、 00:01:54.700 --> 00:01:57.060 工具变量和回归不连续性之间有很多互补性 00:02:00.506 --> 00:02:03.260 回归不连续性的许多计量经济学应用 曾经被称为“模糊” RD 00:02:03.260 --> 00:02:04.520 00:02:04.520 --> 00:02:07.230 00:02:07.230 --> 00:02:11.620 它在截止时不是离散的或确定的 00:02:11.620 --> 00:02:14.900 而只在速率或强度上有着变化 00:02:14.900 --> 00:02:17.737 LATE 框架帮助我们理解这些应用方法 00:02:17.737 --> 00:02:18.740 00:02:18.740 --> 00:02:21.140 并为我们提供了一个清晰的解释 00:02:21.140 --> 00:02:25.000 比如在我与 Victor Lavy 的论文中 00:02:25.000 --> 00:02:28.100 我们使用了 Maimonides 规则 班级规模截断 00:02:28.430 --> 00:02:30.030 那么你这里了解到了什么? 00:02:30.290 --> 00:02:31.820 当然,你可以用线性常数效应模型 来回答这个问题 00:02:31.820 --> 00:02:33.900 00:02:34.200 --> 00:02:36.310 但事实证明我们并不局限于此 00:02:36.310 --> 00:02:39.889 RD 仍然非常强大和有启发性 00:02:40.630 --> 00:02:43.092 即使在这种情况和类型规模下 00:02:43.092 --> 00:02:45.866 截止和感兴趣的变量之间的相关性是局部的 00:02:45.866 --> 00:02:49.133 00:02:49.133 --> 00:02:51.000 甚至可能不是那么强 00:02:52.000 --> 00:02:54.999 所以肯定有着平行发展 00:02:54.999 --> 00:02:56.400 这也很有趣... 00:02:57.253 --> 00:02:59.780 当我们在读研究生时,没有人谈论回归不连续性设计 00:02:59.780 --> 00:03:01.220 00:03:01.220 --> 00:03:02.843 这是其他社会科学家感兴趣的东西 00:03:02.843 --> 00:03:05.300 00:03:05.800 --> 00:03:09.507 它与 LATE 框架一起成长 00:03:09.507 --> 00:03:11.927 我们都曾基于这两种应用方式和方法进行工作 00:03:11.927 --> 00:03:14.565 00:03:14.565 --> 00:03:18.377 而且能看到它的发展并变得如此重要 00:03:18.377 --> 00:03:19.800 我感到非常兴奋 00:03:20.000 --> 00:03:21.767 我认为,这是朝着可靠的识别策略 00:03:21.767 --> 00:03:26.086 因果效应的普遍演变的一部分 00:03:26.086 --> 00:03:27.441 00:03:29.393 --> 00:03:30.642 使计量经济学更多地关注 因果问题而不是模型 00:03:30.642 --> 00:03:33.300 00:03:33.640 --> 00:03:34.650 就未来而言 00:03:34.650 --> 00:03:37.660 我认为 LATE 帮助促进的一件事是 00:03:37.660 --> 00:03:42.008 朝着更具创造性的随机试验迈进 00:03:42.008 --> 00:03:44.400 其中有着一些有趣的东西 00:03:45.500 --> 00:03:48.460 它不可能或直接能被简单地关闭或开启 00:03:48.460 --> 00:03:50.700 00:03:51.000 --> 00:03:54.584 但你可以鼓励或阻止它 00:03:54.584 --> 00:03:58.200 因此,例如,你能通过经济援助 来补贴学校教育 00:03:59.000 --> 00:04:02.080 所以现在我们有了 一个完整的框架来解释这一点 00:04:03.600 --> 00:04:07.113 它打开了对以前似乎不可能的事情 进行随机试验的大门 00:04:07.113 --> 00:04:09.265 00:04:10.300 --> 00:04:12.471 00:04:14.500 --> 00:04:17.864 我们在麻省理工学院 Blueprint实验室中 00:04:17.864 --> 00:04:21.160 大量使用了这一点 00:04:22.360 --> 00:04:26.600 我认为,我们正在以 非常有创意的方式利用随机分配 00:04:28.100 --> 00:04:31.395 - [Isaiah] 与此相关,你是否看到 00:04:31.395 --> 00:04:34.445 有助于计量经济学研究的特定因素? 00:04:34.445 --> 00:04:38.443 你已经提到它与 实际出现的问题有明确的联系 00:04:38.443 --> 00:04:40.300 00:04:40.300 --> 00:04:42.862 并且经验实践通常是一个好主意 00:04:43.290 --> 00:04:45.000 - 这不是一个好主意吗? 00:04:45.700 --> 00:04:50.112 我经常发现自己坐在 一个计量经济学理论研讨会上 00:04:50.700 --> 00:04:52.500 比如哈佛麻省理工学院的研讨会 00:04:53.400 --> 00:04:56.350 我会想,“这个人在解决什么问题? 00:04:56.350 --> 00:04:57.960 谁面对这个问题?” 00:04:57.960 --> 00:04:59.800 而且,你知道… 00:05:01.600 --> 00:05:04.700 如果我问的话 有时会出现令人尴尬的沉默 00:05:04.900 --> 00:05:08.300 或者可能会有一个相当牵强的场景 00:05:08.800 --> 00:05:11.600 我想看看这个工具在哪里有用 00:05:12.500 --> 00:05:14.765 有一些是纯粹的基础工具 00:05:14.765 --> 00:05:16.250 我确实明白这一点 00:05:16.250 --> 00:05:21.735 有些人正在研究的概念基础 00:05:22.600 --> 00:05:25.300 它变得更像数理统计 00:05:25.800 --> 00:05:27.653 我的意思是,我记得一个较早的例子 00:05:27.653 --> 00:05:29.920 那就是我很难理解的随机等连续性的概念 00:05:29.920 --> 00:05:32.500 00:05:32.500 --> 00:05:35.070 我的论文顾问之一,Whitney Newey 00:05:35.070 --> 00:05:36.479 使用它取得了很好的效果 00:05:36.479 --> 00:05:38.821 我当时试图理解这一点 00:05:40.600 --> 00:05:42.034 这真的很基础 00:05:42.034 --> 00:05:45.200 驱动它的不是一个应用方法 00:05:45.890 --> 00:05:47.300 至少不是立即的 00:05:48.600 --> 00:05:53.200 但是大多数事情不是这样的 所以应该有着问题 00:05:53.800 --> 00:05:59.247 我认为这取决于这类事情的卖家 00:06:00.480 --> 00:06:02.250 因为有着机会成本、时间和注意力 00:06:02.250 --> 00:06:05.295 以及理解事情的努力 00:06:05.980 --> 00:06:07.200 00:06:07.400 --> 00:06:08.900 00:06:09.400 --> 00:06:12.900 00:06:12.900 --> 00:06:15.200 00:06:16.097 --> 00:06:18.280 00:06:18.280 --> 00:06:20.700 00:06:20.700 --> 00:06:22.900 00:06:22.900 --> 00:06:26.570 00:06:26.570 --> 00:06:28.347 00:06:28.705 --> 00:06:31.500 00:06:31.500 --> 00:06:34.322 00:06:34.322 --> 00:06:38.304 00:06:38.800 --> 00:06:40.200 00:06:42.500 --> 00:06:45.220 00:06:45.220 --> 00:06:48.600 00:06:49.100 --> 00:06:52.260 00:06:52.260 --> 00:06:54.490 00:06:54.900 --> 00:06:57.205 00:06:57.944 --> 00:07:00.101 00:07:00.101 --> 00:07:02.030 00:07:02.030 --> 00:07:03.720 00:07:04.100 --> 00:07:06.277 00:07:06.277 --> 00:07:08.690 00:07:08.690 --> 00:07:11.066 00:07:11.066 --> 00:07:12.700 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