WEBVTT 00:00:00.000 --> 00:00:02.550 ♪ [music] ♪ 00:00:03.800 --> 00:00:05.800 - [Narrator] Welcome to Nobel Conversations. 00:00:07.040 --> 00:00:08.100 In this episode, 00:00:08.100 --> 00:00:11.570 Josh Angrist and Guido Imbens sit down with Isaiah Andrews 00:00:11.570 --> 00:00:14.600 to discuss how the field of econometrics is evolving. 00:00:16.100 --> 00:00:18.750 - [Isaiah] So, Guido and Josh, you're both pioneers 00:00:18.750 --> 00:00:21.500 in developing tools for empirical research in economics. 00:00:21.500 --> 00:00:22.930 And so I'd like to explore 00:00:22.930 --> 00:00:25.300 where you feel like the field is heading -- 00:00:25.709 --> 00:00:28.079 economics, econometrics, the whole thing. 00:00:28.510 --> 00:00:31.302 To start, I'd be interested to hear 00:00:32.171 --> 00:00:35.200 about whether you feel the way in which 00:00:35.200 --> 00:00:38.510 the local average treatment effects framework took hold 00:00:38.800 --> 00:00:42.187 has any lessons for how new empirical methods in economics 00:00:42.187 --> 00:00:44.300 develop and spread or how they should. 00:00:44.560 --> 00:00:45.960 - [Josh] That's a good question. 00:00:46.610 --> 00:00:47.790 You go first. 00:00:47.790 --> 00:00:49.460 [laughter] 00:00:49.700 --> 00:00:52.940 - [Guido] Yeah, so I think the important thing 00:00:52.940 --> 00:00:58.550 is to come up with good convincing cases 00:00:58.550 --> 00:01:02.207 where the questions are clear 00:01:02.400 --> 00:01:05.720 and where the methods apply in general. 00:01:06.253 --> 00:01:07.560 One thing I -- 00:01:08.192 --> 00:01:12.000 looking back at the subsequent literature. 00:01:12.200 --> 00:01:16.700 So I really like the regression discontinuity literature 00:01:16.700 --> 00:01:19.670 where there were clearly a bunch of really convincing examples 00:01:19.670 --> 00:01:23.378 and that allowed people to think more clearly, 00:01:23.378 --> 00:01:27.200 look harder at the methodological questions. 00:01:27.400 --> 00:01:28.800 Do clear applications 00:01:28.800 --> 00:01:30.600 that then allow you to kind of think about, 00:01:30.600 --> 00:01:33.600 "Wow, does this type of assumption seem reasonable here? 00:01:33.600 --> 00:01:38.000 What kind of things do we not like in the early papers? 00:01:38.500 --> 00:01:39.802 How can we improve things?" 00:01:39.802 --> 00:01:44.210 So having clear applications motivating these literatures 00:01:44.210 --> 00:01:46.400 I think is very helpful. 00:01:46.800 --> 00:01:48.050 - I'm glad you mentioned 00:01:48.050 --> 00:01:49.382 the regression discontinuity, Guido. 00:01:49.382 --> 00:01:53.300 I think there's a lot of complementarity between IV and RD, 00:01:54.700 --> 00:01:57.060 Instrumental Variables and Regression Discontinuity. 00:02:00.506 --> 00:02:03.260 A lot of the econometric applications 00:02:03.260 --> 00:02:04.520 of regression discontinuity 00:02:04.520 --> 00:02:07.230 are what used to be called "fuzzy" RD, 00:02:07.230 --> 00:02:11.620 where, you know, it's not discrete or deterministic at the cutoff 00:02:11.620 --> 00:02:14.900 but just the change in rates or intensity. 00:02:14.900 --> 00:02:17.737 And the LATE framework helps us understand 00:02:17.737 --> 00:02:18.740 those applications 00:02:18.740 --> 00:02:21.140 and gives us a clear interpretation 00:02:21.140 --> 00:02:25.000 for something like in my paper with Victor Lavy, 00:02:25.000 --> 00:02:28.100 where we use Maimonides' rule, the class size cutoffs, 00:02:28.430 --> 00:02:30.030 and what are you getting there? 00:02:30.290 --> 00:02:31.820 Of course, you can answer that question 00:02:31.820 --> 00:02:33.900 with a linear constant effects model, 00:02:34.200 --> 00:02:36.310 but it turns out we're not limited to that, 00:02:36.310 --> 00:02:39.889 and RD is still very powerful and illuminating, 00:02:40.630 --> 00:02:43.092 even when the correlation 00:02:43.092 --> 00:02:45.866 between the cutoff and the variable of interest, 00:02:45.866 --> 00:02:49.133 in this case class size, is partial, 00:02:49.133 --> 00:02:51.000 maybe even not that strong. 00:02:52.000 --> 00:02:54.999 So there was definitely kind of a parallel development. 00:02:54.999 --> 00:02:56.400 It's also interesting -- 00:02:56.600 --> 00:02:59.780 nobody talked about regression discontinuity designs 00:02:59.780 --> 00:03:01.220 when we were in graduate school. 00:03:01.220 --> 00:03:05.300 It was something that other social scientists were interested in, 00:03:05.800 --> 00:03:09.507 and that grew up alongside the LATE framework, 00:03:09.507 --> 00:03:11.927 and we've both done work 00:03:11.927 --> 00:03:14.565 on both applications and methods there, 00:03:14.565 --> 00:03:18.377 and it's been very exciting to see that develop 00:03:18.377 --> 00:03:19.800 and become so important. 00:03:20.000 --> 00:03:21.767 It's part of a general evolution, 00:03:21.767 --> 00:03:26.086 I think, towards credible identification strategies, 00:03:26.086 --> 00:03:27.441 causal effects... 00:03:29.393 --> 00:03:30.642 making econometrics 00:03:30.642 --> 00:03:33.300 more about causal questions than about models. 00:03:33.640 --> 00:03:34.650 In terms of the future, 00:03:34.650 --> 00:03:37.660 I think one thing that LATE has helped facilitate 00:03:37.660 --> 00:03:42.008 is a move towards more creative, randomized trials 00:03:42.008 --> 00:03:44.400 where there's something of interest. 00:03:45.500 --> 00:03:48.460 It's not possible or straightforward 00:03:48.460 --> 00:03:50.700 to simply turn it off or on, 00:03:51.000 --> 00:03:54.584 but you can encourage it or discourage it. 00:03:54.584 --> 00:03:58.200 So you subsidize schooling with financial aid, for example. 00:03:59.000 --> 00:04:02.080 So now we have a whole framework for interpreting that, 00:04:03.600 --> 00:04:07.113 and it opens the doors to randomized trials 00:04:07.113 --> 00:04:10.300 of things that maybe would 00:04:10.300 --> 00:04:12.471 not have seemed possible before. 00:04:14.500 --> 00:04:17.864 We've used that a lot in the work we do on schools in our -- 00:04:17.864 --> 00:04:21.160 in the Blueprint Lab at MIT. 00:04:22.360 --> 00:04:26.600 We're exploiting random assignment in very creative ways, I think. 00:04:28.100 --> 00:04:31.395 - [Isaiah] Related to that, do you see particular factors 00:04:31.395 --> 00:04:34.445 that make for useful research in econometrics? 00:04:34.445 --> 00:04:38.290 You've alluded to it having a clear connection 00:04:38.290 --> 00:04:40.300 to problems that are actually coming up, 00:04:40.300 --> 00:04:42.650 and empirical practice is often a good idea. 00:04:43.290 --> 00:04:45.000 - Isn't it always a good idea? 00:04:45.700 --> 00:04:47.292 I often find myself sitting 00:04:47.292 --> 00:04:50.100 in an econometrics theory seminar, 00:04:50.700 --> 00:04:52.500 say the Harvard MIT seminar, 00:04:53.400 --> 00:04:56.350 and I'm thinking, "What problem is this guy solving? 00:04:56.350 --> 00:04:57.960 Who has this problem?" 00:04:57.960 --> 00:04:59.800 And, you know... 00:05:01.600 --> 00:05:04.700 sometimes there's an embarrassing silence if I ask 00:05:04.900 --> 00:05:08.300 or there might be a fairly contrived scenario. 00:05:08.800 --> 00:05:11.600 I want to see where the tool is useful. 00:05:12.500 --> 00:05:14.765 There are some purely foundational tools. 00:05:14.765 --> 00:05:16.250 I do take the point. 00:05:16.250 --> 00:05:21.735 There are people who are working on conceptual foundations of ... 00:05:22.600 --> 00:05:25.300 it becomes more like mathematical statistics. 00:05:25.800 --> 00:05:27.653 I mean, I remember an early example of that 00:05:27.653 --> 00:05:29.920 that I struggled to understand 00:05:29.920 --> 00:05:32.500 was the idea of stochastic equicontinuity, 00:05:32.500 --> 00:05:35.070 which one of my thesis advisors, Whitney Newey, 00:05:35.070 --> 00:05:36.479 was using to great effect, 00:05:36.479 --> 00:05:38.821 and I was trying to understand that. 00:05:40.600 --> 00:05:42.034 It's really foundational. 00:05:42.034 --> 00:05:45.200 it's not an application that's driving that -- 00:05:45.890 --> 00:05:47.300 at least not immediately. 00:05:48.600 --> 00:05:53.200 But most things are not like that, and so there should be a problem. 00:05:53.800 --> 00:05:59.100 And I think it's on the seller of that sort of thing, 00:06:00.480 --> 00:06:02.250 because there's opportunity cost, 00:06:02.250 --> 00:06:05.295 the time and attention, and effort to understand things. 00:06:05.980 --> 00:06:07.200 It's on the seller to say, 00:06:07.400 --> 00:06:08.900 "Hey, I'm solving this problem, 00:06:09.400 --> 00:06:12.900 and here's a set of results that show that it's useful, 00:06:12.900 --> 00:06:15.200 and here's some insight that I get." 00:06:16.200 --> 00:06:18.280 - [Isaiah] As you said, Josh, there's been a move 00:06:18.280 --> 00:06:20.700 in the direction of thinking more about causality 00:06:20.700 --> 00:06:22.900 in economics and empirical work in economics. 00:06:22.900 --> 00:06:24.800 Any consequences of the -- 00:06:24.800 --> 00:06:26.570 the spread of that view that surprised you 00:06:26.570 --> 00:06:28.347 or anything that you view as downsides 00:06:28.705 --> 00:06:31.400 of the way that empirical economics has gone? 00:06:31.500 --> 00:06:34.322 - Sometimes I see somebody does IV, 00:06:34.322 --> 00:06:38.304 and they get a result which seems implausibly large. 00:06:38.800 --> 00:06:40.200 That's the usual case. 00:06:42.500 --> 00:06:45.220 So it might be an extraordinarily large 00:06:45.220 --> 00:06:48.600 causal effect of some relatively minor intervention, 00:06:49.100 --> 00:06:52.260 which was randomized or for which you could make a case 00:06:52.260 --> 00:06:54.490 that there's a good design. 00:06:54.900 --> 00:06:57.205 And then when I see that, 00:06:57.944 --> 00:07:00.101 I think it's very hard for me to believe 00:07:00.101 --> 00:07:02.030 that this relatively minor intervention 00:07:02.030 --> 00:07:03.720 has such a large effect. 00:07:04.100 --> 00:07:06.277 The author will sometimes resort 00:07:06.277 --> 00:07:08.690 to the local average treatment effects theorem 00:07:08.690 --> 00:07:11.066 and say, "Well, these compliers, 00:07:11.066 --> 00:07:12.700 they're special in some way." 00:07:13.300 --> 00:07:15.800 And they just benefit extraordinarily 00:07:15.800 --> 00:07:17.600 from this intervention. 00:07:18.100 --> 00:07:21.175 I'm reluctant to take that at face value. 00:07:21.175 --> 00:07:23.750 I think often when effects are too big, 00:07:24.300 --> 00:07:26.780 it's because the exclusion restriction is failing, 00:07:26.780 --> 00:07:29.456 so you don't really have the right endogenous variable 00:07:29.456 --> 00:07:31.380 to scale that result. 00:07:32.000 --> 00:07:35.700 And so I'm not too happy to see 00:07:36.937 --> 00:07:40.022 a generic heterogeneity argument 00:07:40.022 --> 00:07:41.760 being used to excuse something 00:07:41.760 --> 00:07:43.800 that I think might be a deeper problem. 00:07:45.190 --> 00:07:47.358 - [Guido] I think it played somewhat of an unfortunate role 00:07:47.358 --> 00:07:50.083 in the discussions between reduced form 00:07:50.083 --> 00:07:51.700 and structural approaches, 00:07:51.700 --> 00:07:55.510 where I feel that wasn't quite right. 00:07:56.090 --> 00:07:58.810 The instrumental variables assumptions 00:07:58.810 --> 00:08:03.483 are at the core, structural assumptions about behavior -- 00:08:03.483 --> 00:08:05.200 they were coming from economic... 00:08:07.100 --> 00:08:09.900 thinking about the economic behavior of agents, 00:08:10.300 --> 00:08:15.100 and somehow it got pushed in a direction 00:08:15.100 --> 00:08:17.600 that I think wasn't really very helpful. 00:08:20.426 --> 00:08:21.663 I think, initially, 00:08:22.800 --> 00:08:24.067 we wrote things up, 00:08:24.067 --> 00:08:26.480 it was describing what was happening. 00:08:26.480 --> 00:08:29.783 There were a set of methods people were using. 00:08:29.783 --> 00:08:32.111 We clarified what those methods were doing 00:08:32.811 --> 00:08:38.361 and in a way that I think contain a fair amount of insight. 00:08:39.100 --> 00:08:42.050 But it somehow got pushed into a corner 00:08:42.050 --> 00:08:45.379 that I don't think was necessarily very helpful. 00:08:45.379 --> 00:08:48.604 - In just the language of reduced form versus structural, 00:08:48.604 --> 00:08:50.306 I find kind of funny in the sense 00:08:50.306 --> 00:08:52.985 that the local average treatment effect model, 00:08:52.985 --> 00:08:54.154 the potential outcomes model 00:08:54.154 --> 00:08:56.110 is a nonparametric structural model, 00:08:56.110 --> 00:08:58.600 if you want to think about it, as you suggested, Guido. 00:08:58.600 --> 00:09:01.129 So there's something a little funny 00:09:01.129 --> 00:09:03.505 about putting these two things in opposition when -- 00:09:03.505 --> 00:09:05.116 - [Guido] Yes. - [Josh] That language, of course, 00:09:05.116 --> 00:09:08.371 comes from the simultaneous equations framework 00:09:08.371 --> 00:09:09.641 that we inherited. 00:09:10.400 --> 00:09:11.440 It has the advantage 00:09:11.440 --> 00:09:14.160 that people seem to know what you mean when you use it, 00:09:14.160 --> 00:09:16.240 but that might be that people are hearing different -- 00:09:16.240 --> 00:09:18.300 different people are hearing different things. 00:09:18.300 --> 00:09:20.480 - [Guido] Yeah. I think reduced form has become 00:09:20.480 --> 00:09:22.200 used in a little bit of the pejorative way... 00:09:22.200 --> 00:09:23.540 - [Josh] Sometimes. 00:09:25.104 --> 00:09:28.250 ...which is not really quite what it was originally intended for. 00:09:30.100 --> 00:09:33.090 - [Isaiah] I guess something else that strikes me in thinking about 00:09:33.090 --> 00:09:35.645 the effects of the local average treatment effect framework 00:09:35.645 --> 00:09:37.676 is that often folks will appeal 00:09:37.676 --> 00:09:40.000 to a local average treatment effects intuition 00:09:40.000 --> 00:09:42.358 for settings well beyond ones 00:09:42.358 --> 00:09:44.963 where any sort of formal result has actually been established. 00:09:45.440 --> 00:09:49.180 And I'm curious, given all the work that you guys did 00:09:49.180 --> 00:09:52.390 to establish LATE results in different settings, 00:09:52.390 --> 00:09:54.415 I'm curious, any thoughts on that? 00:09:55.360 --> 00:09:57.306 - I think there's going to be a lot of cases 00:09:57.306 --> 00:10:02.200 where the intuition does get you some distance, 00:10:02.800 --> 00:10:04.989 but it's going to be somewhat limited, 00:10:04.989 --> 00:10:07.600 and establishing formal results there 00:10:08.400 --> 00:10:09.490 may be a little tricky 00:10:09.490 --> 00:10:12.700 and then maybe only work in special circumstances, 00:10:14.600 --> 00:10:16.540 and you end up with a lot of formality 00:10:16.540 --> 00:10:19.500 that may not quite capture the intuition. 00:10:19.900 --> 00:10:21.550 Sometimes I'm somewhat uneasy with them, 00:10:21.550 --> 00:10:24.438 and they are not necessarily the papers I would want to write, 00:10:25.148 --> 00:10:27.819 but I do think intuition 00:10:27.819 --> 00:10:31.217 often does capture part of the problem. 00:10:33.100 --> 00:10:36.300 I think, in some sense, we were very fortunate there 00:10:36.900 --> 00:10:39.250 in the way that the LATE paper got handled at the journal, 00:10:39.250 --> 00:10:41.766 so that, actually, the editor, made it much shorter 00:10:42.100 --> 00:10:46.300 and that allowed us to focus on very clear, crisp results. 00:10:49.924 --> 00:10:51.770 There's a somewhat unfortunate tendency 00:10:51.770 --> 00:10:53.118 in the econometrics literature 00:10:53.118 --> 00:10:55.100 of having the papers get longer and longer. 00:10:55.100 --> 00:10:56.550 - Well, you should be able to fix that, man. 00:10:56.550 --> 00:10:58.915 - I'm trying to fix that. [laughter] 00:10:58.915 --> 00:11:01.625 But I think this is an example where it's very clear 00:11:01.625 --> 00:11:03.097 that having it be short is actually -- 00:11:03.097 --> 00:11:04.750 - You should have imposed that no paper 00:11:04.750 --> 00:11:06.802 can be longer than the LATE paper. 00:11:07.269 --> 00:11:09.617 - That... wow! That may be great. 00:11:09.617 --> 00:11:11.685 - At least no theory, no theory paper. 00:11:11.892 --> 00:11:14.300 - Yeah, and I think... 00:11:14.500 --> 00:11:16.800 I'm trying very hard to get the papers to be shorter, 00:11:16.800 --> 00:11:19.514 and I think there is a lot of value today 00:11:19.514 --> 00:11:21.573 because it's often the second part of the paper 00:11:21.573 --> 00:11:25.049 that doesn't actually get you much further 00:11:25.049 --> 00:11:26.395 in understanding things, 00:11:27.000 --> 00:11:29.870 and it does make things much harder to read. 00:11:32.426 --> 00:11:36.179 It goes back to how I think econometrics should be done. 00:11:36.179 --> 00:11:38.070 You should focus on -- 00:11:38.700 --> 00:11:41.300 It should be reasonably close to empirical problems. 00:11:41.500 --> 00:11:43.900 They should be very clear problems. 00:11:44.800 --> 00:11:48.900 But then often the theory doesn't need to be quite so long. 00:11:48.900 --> 00:11:50.010 - [Josh] Yeah. 00:11:51.100 --> 00:11:54.670 - I think things have gone a little off track. 00:11:56.260 --> 00:11:57.750 - [Isaiah] A relatively recent change 00:11:57.750 --> 00:12:00.230 has been a seeming big increase in demand 00:12:00.230 --> 00:12:03.765 for people with econometrics causal effect estimation skills 00:12:03.765 --> 00:12:04.994 in the tech sector. 00:12:04.994 --> 00:12:07.563 I'm interested, do either of you have thoughts 00:12:07.563 --> 00:12:09.840 of how that's going to interact 00:12:09.840 --> 00:12:11.600 with the development of empirical methods 00:12:11.600 --> 00:12:13.950 or empirical research in economics going forward? 00:12:14.600 --> 00:12:16.770 - [Josh] Well, there's sort of a meta point, 00:12:16.770 --> 00:12:21.000 which is, there's this new kind of employer, 00:12:21.800 --> 00:12:27.530 the Amazons and the Uber, and the TripAdvisor world, 00:12:28.000 --> 00:12:29.300 and I think that's great. 00:12:29.300 --> 00:12:32.030 I like to tell my students about that. 00:12:32.600 --> 00:12:35.500 At MIT we have a lot of computer science majors -- 00:12:35.500 --> 00:12:37.000 that's our biggest major. 00:12:37.400 --> 00:12:42.362 I try to seduce some of those folks into economics by saying 00:12:43.228 --> 00:12:46.700 you can go work for these companies 00:12:46.700 --> 00:12:49.250 that people are very keen to work for 00:12:49.250 --> 00:12:50.800 because the work seems exciting, 00:12:52.000 --> 00:12:54.250 that the skills that you get in econometrics 00:12:54.250 --> 00:12:56.100 are as good or better 00:12:56.100 --> 00:12:59.736 than any competing discipline has to offer. 00:12:59.736 --> 00:13:01.100 So you should at least 00:13:01.400 --> 00:13:04.200 take some econ, take some econometrics, and some econ. 00:13:04.800 --> 00:13:07.000 I did a fun project with Uber 00:13:07.600 --> 00:13:09.920 on labor supply of Uber drivers, 00:13:09.920 --> 00:13:12.805 and it was very, very exciting to be part of that. 00:13:13.100 --> 00:13:15.400 Plus I got to drive for Uber for a while, 00:13:15.900 --> 00:13:17.730 and I thought that was fun too. 00:13:17.730 --> 00:13:19.231 I did not make enough 00:13:19.231 --> 00:13:22.616 that I was tempted to give up my MIT job, 00:13:22.616 --> 00:13:25.100 but I enjoyed the experience. 00:13:25.230 --> 00:13:27.534 I see a potential challenge 00:13:27.534 --> 00:13:30.900 to our model of graduate education here, 00:13:31.700 --> 00:13:36.068 which is, if we're training people to go work at Amazon, 00:13:37.900 --> 00:13:41.190 it's not clear why we should be paying 00:13:41.190 --> 00:13:42.900 graduate stipends for that. 00:13:43.200 --> 00:13:47.280 Why should the taxpayer effectively be subsidizing that. 00:13:47.280 --> 00:13:51.180 Our graduate education in the US Is generously subsidized, 00:13:51.180 --> 00:13:53.160 even in private universities, 00:13:53.160 --> 00:13:56.477 it's ultimately -- there's a lot of public money there, 00:13:56.477 --> 00:13:59.300 and I think the traditional rationale for that is, 00:13:59.643 --> 00:14:01.992 we were training educators and scholars, 00:14:01.992 --> 00:14:05.657 and there's a great externality from the work that we do, 00:14:05.657 --> 00:14:07.910 it's either the research externality, 00:14:07.910 --> 00:14:09.557 or a teaching externality. 00:14:10.100 --> 00:14:13.389 But if many of our students are going to work 00:14:13.389 --> 00:14:14.688 in the private sector -- 00:14:16.300 --> 00:14:17.414 that's fine, 00:14:19.000 --> 00:14:21.700 but maybe their employers should pay for that. 00:14:22.120 --> 00:14:23.370 - For me, it's [just] so different 00:14:23.370 --> 00:14:26.780 from people working for consulting firms. 00:14:27.200 --> 00:14:28.780 It's not clear to me 00:14:28.780 --> 00:14:32.836 that the number of jobs in academics has changed. 00:14:33.370 --> 00:14:36.325 - I feel like this is a growing sector, 00:14:36.325 --> 00:14:39.289 whereas consulting -- you're right to raise that, 00:14:39.289 --> 00:14:42.100 it might be the same for consulting. 00:14:44.846 --> 00:14:47.500 I'm placing more and more students in these businesses, 00:14:47.500 --> 00:14:49.467 so it's on my mind, in a way, 00:14:49.467 --> 00:14:53.960 that I've not been attentive to consulting jobs. 00:14:53.960 --> 00:14:56.920 Consulting was always important, 00:14:56.920 --> 00:14:58.950 and I think also there's some movement 00:14:58.950 --> 00:15:01.140 from consulting back into research -- 00:15:01.140 --> 00:15:02.723 it's a little more fluid. 00:15:03.900 --> 00:15:07.630 A lot of the work in both domains, 00:15:07.630 --> 00:15:09.430 I have to say, it's not really different 00:15:09.430 --> 00:15:12.730 but people who are working in the tech sector 00:15:12.730 --> 00:15:15.480 are doing things that are potentially of scientific interest, 00:15:15.480 --> 00:15:16.800 but mostly it's hidden. 00:15:17.100 --> 00:15:18.550 Then you really have to say 00:15:18.550 --> 00:15:20.900 why is the government paying for this? 00:15:22.477 --> 00:15:23.732 I mean to Guido's point, 00:15:23.732 --> 00:15:26.783 I guess there's a data question here of, 00:15:26.783 --> 00:15:32.772 has the total [no-neck] say for-profit sector employment 00:15:32.772 --> 00:15:35.595 of econ Ph.D. program graduates increased 00:15:35.595 --> 00:15:38.290 or has it just been a substitution from finance 00:15:38.290 --> 00:15:40.200 and consulting towards tech? 00:15:40.300 --> 00:15:42.300 - I may be reacting to something 00:15:42.300 --> 00:15:44.300 that's not really happening. 00:15:44.400 --> 00:15:45.890 - I've actually done some work 00:15:45.890 --> 00:15:48.200 with some of these tech companies. 00:15:49.100 --> 00:15:52.200 I don't disagree with Josh's point that we need to think 00:15:52.200 --> 00:15:53.675 a little bit about the funding model 00:15:53.675 --> 00:15:56.390 who is, in the end, paying for the graduate education. 00:15:56.913 --> 00:15:59.400 But from a scientific perspective, 00:15:59.980 --> 00:16:02.840 not only do these places have great data 00:16:02.840 --> 00:16:05.112 and nowadays they tend to be very careful with that 00:16:05.112 --> 00:16:07.100 for privacy reasons, 00:16:07.380 --> 00:16:08.900 but they also have great questions. 00:16:10.200 --> 00:16:13.929 I find it very inspiring to listen to the people there 00:16:13.929 --> 00:16:15.950 and see what kind of questions they have, 00:16:15.950 --> 00:16:17.330 and often they're questions 00:16:18.200 --> 00:16:21.241 that also come up outside of these companies. 00:16:21.241 --> 00:16:27.430 I have a couple of papers with Raj Chetty and Susan Athey, 00:16:27.430 --> 00:16:31.600 where we look at ways of combining experimental data 00:16:31.600 --> 00:16:33.274 and observational data. 00:16:35.500 --> 00:16:38.600 Raj Chetty was interested in what is the effect 00:16:38.600 --> 00:16:42.893 of early childhood programs on outcomes later in life, 00:16:42.893 --> 00:16:46.330 not just kind on test scores but on earnings and stuff, 00:16:46.330 --> 00:16:48.300 and we kind of developed methods 00:16:48.600 --> 00:16:51.500 that would help you shed light on that under some -- 00:16:52.718 --> 00:16:53.868 in some settings, 00:16:53.868 --> 00:16:56.920 and the same problems came up 00:16:56.920 --> 00:17:00.533 in these tech company settings. 00:17:00.800 --> 00:17:03.240 And so, from my perspective, 00:17:03.240 --> 00:17:05.420 it's the same kind of -- 00:17:05.420 --> 00:17:07.600 I was talking to people doing empirical work. 00:17:07.600 --> 00:17:09.700 I tried to kind of look at these specific problems 00:17:09.700 --> 00:17:13.370 and then try to come up with more general problems, 00:17:15.110 --> 00:17:18.230 reformulating the problems at a higher level, 00:17:18.500 --> 00:17:22.900 so that I can think about solutions that work in a range of settings. 00:17:23.400 --> 00:17:24.933 And so from that perspective, 00:17:24.933 --> 00:17:27.570 the interactions with the tech companies 00:17:27.570 --> 00:17:30.300 are just very valuable and very useful. 00:17:31.700 --> 00:17:35.204 We do have students now doing internships there 00:17:35.204 --> 00:17:38.516 and then coming back and writing more interesting theses 00:17:38.516 --> 00:17:43.400 as a result of their experiences there. 00:17:44.600 --> 00:17:47.020 - [Narrator] If you'd like to watch more Nobel Conversations, 00:17:47.020 --> 00:17:48.200 click here. 00:17:48.200 --> 00:17:50.500 Or if you'd like to learn more about econometrics, 00:17:50.500 --> 00:17:53.100 check out Josh's "Mastering Econometrics" series. 00:17:53.700 --> 00:17:56.720 If you'd like to learn more about Guido, Josh, and Isaiah, 00:17:56.720 --> 00:17:58.300 check out the links in the description. 00:17:59.036 --> 00:18:01.495 ♪ [music] ♪