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♪ [music] ♪

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- [Narrator] Welcome[br]to Nobel Conversations.

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In this episode, Josh Angrist [br]and Guido Imbens,

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sit down with Isaiah Andrews

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to discuss how their research[br]was initially received

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and how they responded [br]to criticism.

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- [Isaiah] At the time, [br]did you feel like

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you were on to something,

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you felt this was the beginning[br]of a whole line of work

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that you felt like was going [br]to be important or...?

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- [Guido] Not so much[br]that it was a whole line of work,

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but certainly I felt like, [br]"Wow, this --"

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- [Josh] We've proved something [br]we didn't know before,

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that it was worth knowing.

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- Yeah, going back to the...

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compared to my job market[br]paper or something --

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No, I felt this was actually [br]a very clear, crisp result.

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- But there was definitely [br]a mixed reception

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and I don't think anybody [br]said that,

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"Oh, well, this is [br]already something

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which is the nightmare scenario[br]for a researcher

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where you think[br]you've discovered something

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and then somebody else says, [br]"Oh, I knew that."

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But there definitely was [br]a need to convince people

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that this was worth knowing,[br]that instrumental variables

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estimates a causal effect [br]for compliers.

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- Yeah, but even though[br]it took a long time

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to convince a bigger audience,

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sometimes even fairly quickly, [br]the reception was pretty good

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among a small group of people.

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Gary clearly liked it a lot [br]from the beginning,

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and I remember...

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because at that point[br]Josh had left for Israel,

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but I remember explaining it [br]to Don Rubin,

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and he was like, "You know, [br]this really is something here."

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- Not right away though.

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Don took some convincing.

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By the time you got to Don,

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there have been [br]some back and forth with him

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and in correspondence, actually.

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- But I remember at some point [br]getting a call or email from him

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saying that he was sitting [br]at the airport in Rome

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and looking at the paper [br]and thinking,

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"Yeah, no actually, [br]you guys are onto something."

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- We were happy about that.

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But that took longer [br]than I think you remember.

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It wasn't right away.

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[laughter]

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Because I know[br]that I was back in Israel

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by the time that happened.

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I'd left for Israel [br]in the summer of --

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I was only at Harvard [br]for two years.

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We had that one year.

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It is remarkable, I mean, that[br]one year was so fateful for us.

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- [Guido] Yes.

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I think we understood there was[br]something good happening,

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but maybe we didn't think it was[br]life-changing, only in retrospect.

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♪ [music] ♪

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- [Isaiah] As you said, it sounds[br]like a small group of people

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were initially quite receptive,

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perhaps took some time[br]for a broader group of people

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to come around to seeing [br]the LATE framework

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as a valuable way to look [br]at the world.

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I guess, in over[br]the course of that,

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were their periods [br]where you thought,

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maybe the people saying [br]this wasn't a useful way

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to look at the world were right?

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Did you get discouraged? [br]How did you think about?

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- I don't think I was discouraged,

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but the people who were saying[br]that we're smart people,

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well-informed econometricians,

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sophisticated readers,

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and I think the substance[br]of the comment

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was this is not what [br]econometrics is about.

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Econometrics being transmitted [br]at that time was about structure.

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There was this idea that[br]there's structure in the economy,

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and it's our job to discover it,

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and what makes its structure[br]is it's essentially invariant.

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And so we're saying, [br]in the LATE theorem,

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that every instrument produces[br]its own causal effect,

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which is in contradiction to that[br]to some extent,

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and so that was [br]where the tension was.

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People didn't want [br]to give up that idea.

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- Yeah, I remember once [br]people were started

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arguing more vocally against that,

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that never really [br]bothered me that much.

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It seemed clear that [br]we had a result there,

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and it became somewhat [br]controversial,

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but controversial in a good way.

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It was clear that people felt

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they had to come out[br]against it because --

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- Well, I think we think[br]it's good now.

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We might not have loved it [br]at the time.

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I remember being[br]somewhat more upset --

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there was some dinner [br]where someone said,

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"No, no, no, [br]that paper with Josh --

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that was doing a disservice[br]to the profession."

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- We definitely had [br]reactions like that.

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- At some level, that may be [br]indicative of the culture

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in general in economics [br]at the time.

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I thought back later, [br]what if that happened now?

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If I was a senior person[br]sitting in that conversation,

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I would call that out because[br]it really was not appropriate --

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- [Josh] It wasn't so bad.

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I think the criticism is...

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It wasn't completely misguided.

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It was maybe wrong.

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No, no, but you can say [br]that paper is wrong,

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but it's saying that

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it's a disservice [br]to the profession --

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- that's not really --[br]- [Isaiah] It's a bit personal.

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- Yes, and doing that not to me

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but in front of [br]my senior colleagues.

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- But nobody was saying [br]the result was wrong,

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and I remember also,

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some of the comments [br]were thought-provoking.

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So we had some negative reviews,

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I think, on the average [br]causal response paper.

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Somebody said, "These compliers,[br]you can't figure out who they are."

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It's one thing to say[br]you're estimating

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the effect of treatment[br]on the treated

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or something like that.

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You can tell me who's treated

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people in the CPS,[br]you can't tell me who's a complier.

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So that was a legitimate challenge.

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- That's certainly fair,[br]and I can see why

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that part made people[br]a little uneasy and uncomfortable.

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But at the same time,

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because it showed that you couldn't[br]really go beyond that,

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it was a very useful thing [br]to realize.

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I remember on the day[br]we got to the key result

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that I was thinking,[br]"Wow, this is as good as it gets.

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Here we actually have[br]an insight, but it clearly --"

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- And we had to sell it [br]at some point.

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For quite a few years, [br]we had to sell it,

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and it's proven to be quite useful.

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I don't think we understood that[br]it would be so useful at the time.

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- No.

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- I did feel early on[br]this was a substantial insight.

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- [Josh] Yeah we'd done something.

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- But I did not think [br]goals were there.

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- I don't think we were aiming [br]for the Nobel.

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[laughter]

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We were very happy to get[br]that note in <i>Econometrica.</i>

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♪ [music] ♪

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- [Isaiah] Are there factors [br]or are ways of approaching problems

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that lead people to be better [br]at recognizing the good stuff

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and taking the time to do it [br]as opposed to dismissing it?

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- [Josh] Sometimes [br]I think it's helpful.

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If you're trying to [br]convince somebody

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that you have something [br]useful to say

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and maybe they don't [br]speak your language,

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you might need [br]to learn their language.

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- Yes, yes, exactly.

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- That's what we did with Don,[br]we figured out how to --

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I remember we had a very hard time

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explaining the exclusion[br]restriction to Don,

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maybe rightfully so,

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I think Guido and I [br]eventually figured out

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that it wasn't formulated [br]very clearly,

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and we came up [br]with a way to do that

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in the potential outcomes framework

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that I think worked[br]for the three of us.

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- [Guido] Yeah.

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Well, it worked[br]for the bigger literature,

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but I think what you're saying [br]there is exactly right,

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you need to figure out [br]how not just say,

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"Okay, I've got this language,[br]and this this works great,

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and I've got to convince[br]someone else to use the language.

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You could first figure out [br]what language they're using,

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and then, only then, [br]can you try to say,

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"Well, but here you're thinking[br]of it this way."

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But that's actually [br]a pretty hard thing to do.

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You get someone[br]from a different discipline,

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convincing them, two junior faculty[br]in a different department

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actually have something [br]to say to you

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that takes a fair amount of effort.

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- Yeah, I wrote Don [br]a number of times,

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in fairly long letters.

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I remember thinking [br]this is worth doing,

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that if I could convince Don,

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that would validate[br]the framework to some extent.

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- I think both you and Don

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were a little bit more confident [br]that you were right.

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- Well, we used to argue a lot,

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and you would sometimes [br]referee those.

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[laughter]

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That was fun.

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It wasn't hurtful.

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- I remember it getting [br]a little testy once.

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We had lunch in The Faculty Club,

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and we were talking about [br]the draft lottery paper.

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We were talking about "never takes"

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as people wouldn't serve[br]in the military

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irrespective of whether[br]they were getting drafted,

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and you or Don said something

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about shooting yourself[br]in the foot...

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[laughter]

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...as a way of getting out[br]of the military

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and that may be [br]the exclusion restriction

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for never takes wasn't working,

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and then the other one was going,

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"Well, yes, you could do that,

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but why would you want [br]to shoot yourself in the foot?"

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[laughter]

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It got a little there...

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- I usually go for moving[br]to Canada for my example,

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when I'm teaching that.

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[laughter]

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But things are tricky,

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I get students coming[br]from Computer Science,

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and they want to do things [br]on causal inference,

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and it takes a huge amount [br]of effort to figure out

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how they're actually thinking [br]about a problem

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and whether[br]there's something there.

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And so, now over the years,

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I've got a little more appreciation[br]for the fact

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that Don was actually willing to --

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It took him a while, [br]but he did engage first with Josh

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and then with both of us,

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rather than dismissing and saying,

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"Okay, well, I can't figure out[br]what these guys are doing,

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and it's probably just [br]not really that interesting."

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- Everybody always wants [br]to figure out quickly.

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You want to save time,

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and you want to save [br]your brain cells

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for other things.

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The fastest route to that[br]is to figure out

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why you should dismiss something.

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- Yes.

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- I don't need[br]to spend time on this.

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♪ [music] ♪

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- [Narrator] If you'd like [br]to watch more Nobel Conversations,

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click here,

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or if you'd like to learn[br]more about econometrics,

0:10:18.640,0:10:21.240
check out Josh's[br]Mastering Econometrics series.

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If you'd like to learn more[br]about Guido, Josh, and Isaiah,

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check out the links [br]in the description.

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♪ [music] ♪