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- [Narrator] Welcome to
Nobel conversations.
In this episode, Josh Angrist
and Guido Imbens,
sit down with Isaiah Andrews
to discuss how their research
was initially received
and how they responded
to criticism.
At the time, did you feel like
you are on to something,
you felt this was the beginning
of a whole line of work
that you felt like was going
to be important or...?
Not so much that it was
a whole line of work,
but certainly I felt like,
"Wow, this--"
- [Josh] We proved something
that people didn't know before,
that it was worth knowing.
Yeah, going back compared to
my job market papers having--
I felt this was actually
a very clear crisp result.
But there were definitely
was mixed reception
and I don't think anybody
said that,
"Oh, wow, this is already,
something."
No, which is the nightmare scenario
for a researcher
where you think you've
discovered something
and then somebody else says,
"Oh, I knew that."
But there were definitely was
a need to convince people
that this was worth knowing,
that instrumental variables
estimates a causal effect
for compliers.
Yeah, but even though it
took a long time
to convince a bigger audience,
sometimes even fairly quickly,
the reception was pretty good
among a small group of people.
Gary, clearly liked it a lot
from the beginning
and I remember, because at that point
Josh had left for Israel,
but I remember explaining it
to Don Ruben
and he was like,
"Yeah, this really is something here."
Not right away though,
Don took some convincing.
By the time you got to Don,
there have been some back
and forth with him
and in correspondence actually.
But I remember at some point
getting a call or email from him
saying that he was sitting
at the airport in Rome
and looking at the paper
and thinking,
"Yeah, no actually,
you guys are onto something."
We were happy about that
but that took longer
than I think you remember.
It wasn't right away
[laughter]
because I know that I was back
in Israel by the time that happened.
I'd left for Israel
in the summer of--
I was only at Harvard
for two years.
We had that one year.
It is remarkable, I mean, that
one year was so fateful for us.
- [Guido] Yes.
I think we understood there was
something good happening,
but maybe we didn't think it was
life-changing, only in retrospect.
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- [Isaiah] As you said, it sounds like
a small group of people
were initially quite receptive,
perhaps took some time for
a broader group of people
to come around to seeing
the LATE framework
as a valuable way to look
at the world.
I guess, in over the course of that,
were their periods
where you thought,
maybe the people saying
this wasn't a useful way
to look at the world were right?
Did you get discouraged?
How did you think about?
I don't think I was discouraged
but the people who were saying
that we're smart people,
well informed econometricians,
sophisticated readers
and I think the substance
of the comment was,
this is not what econometrics
is about.
Econometrics was being transmitted
at that time was about structure.
There was this idea that
there's structure in the economy
and it's our job to discover it
and what makes it structure
is it's essentially invariant
and so we're saying,
in the LATE theorem,
that every instrument produces
its own causal effect,
which is in contradiction to that
to some extent
and so that was
where the tension was.
People didn't want
to give up that idea.
Yeah, I remember once
people were started
arguing more vocally against that,
that never really
bothered me that much.
It seemed clear that
we had a result there
and it became somewhat
controversial,
but controversial in a good way.
It was clear that people felt
they had to come out against it
because--
Well, I think what
we think it's good now
we might not have loved it
at the time.
I remember being somewhat,
the more upset--
there was some dinner
where someone said,
"No, no, no, that paper with Josh,
that was doing a disservice
to the profession."
We definitely had
reactions like that.
At some level, that may be
indicative of the culture
in general in economics
at the time.
I thought back later,
what if that'd happened now,
if I was a senior person sitting
in that conversation,
I would call that out because it
really was not appropriate--
- [Josh] It wasn't so bad.
I think the criticism is--
It wasn't completely misguided,
it was maybe wrong.
No, no, but you can say
the paper is wrong
but it's saying that
it's a disservice
to the profession,
that's not really--
Personal.
Yes, and doing that, not to me,
but in front of
my senior colleagues.
But nobody was saying
the result was wrong
and I remember also,
some of the comments
were thought-provoking
so we had some negative reviews,
I think on the average
causal response paper.
Somebody said, "These compliers
you can't figure out who they are."
Right, it's one thing to say
you're estimating
the effect of treatment
on the treated
or something like that.
You can tell me who's treated,
people in the CPS,
you can't tell me who's a complier.
So that was a legitimate challenge.
That's certainly fair
and I can see why
that part made people
a little uneasy and uncomfortable.
But at the same time,
because it showed that you couldn't
really go beyond that,
it was very useful thing
to realize.
I remember on the day,
we got to the key result
that I was thinking,
"Wow, this is as good as it gets.
Here we actually have an insight
but clearly--"
And we had to sell it
at some point.
For quite a few years,
we had to sell it
and it's proven to be quite useful.
I don't think we understood that
it would be so useful at the time.
No.
I did feel early on this was
a substantial insight.
- [Josh] Yeah we [did] something.
But I did not think
goals were there.
I don't think we were aiming
for the Nobel.
[laughter]
We were very happy to get
that note in Econometrica.
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- [Isaiah] Are there factors
or are ways of approaching problems
that lead people to be better
at recognizing the good stuff
and taking the time to do it
as opposed to dismissing it?
- [Josh] Sometimes
I think it's helpful.
If you're trying to
convince somebody
that you have something
useful to say
and maybe they don't
speak your language,
you might need
to learn their language.
Yes, yes, exactly.
That's what we did with Don,
we figured out how to--
I remember we had a very hard time
explaining the exclusion restriction
to Don,
maybe rightfully so,
I think Guido and I
eventually figured out
that it wasn't formulated
very clearly,
and we came up
with a way to do that
in the potential outcomes framework
that I think worked
for the three of us.
- [Guido] Yeah.
Well, it worked for
the bigger literature
but I think what you're saying
there is exactly right,
you need to figure out
how not just say,
"Okay well, I've got this language
and this this works great
and I've got to convince someone
else to use the language.
You could first figure out
what language they're using
and then only then,
can you try to say,
"Well, but here you thinking of it
this way,"
but that's actually
a pretty hard thing to do,
you get someone from
a different discipline,
convincing them, two junior faculty
in a different department
actually have something
to say to you,
that takes a fair amount of effort.
Yeah, I wrote Don
a number of times,
in fairly long letters.
I remember thinking
this is worth doing,
that if I could convince Don
that would validate the framework
to some extent.
I think both you and Don were
a little bit more confident
that you were right.
Well, we used to argue a lot
and you would sometimes
referee those.
[laughter]
That was fun.
It wasn't hurtful.
I remember it getting
a little testy once,
we had lunch in The Faculty Club
and we're talking about
the draft lottery paper.
We were talking about "never takes"
[as people who wound serve]
in the military irrespective of
whether they were getting drafted
and you or Don said something
about shooting yourself in the foot,
[laughter]
as a way of getting
out of the military
and that may be
the exclusion restriction
for never takes wasn't working
and then the other one was going,
"Well, yes you could do that
but why would you want
to shoot yourself in the foot?"
[laughter]
It got a little [out of hand there]--
I usually go for moving to Canada,
for my example,
when I'm teaching that.
[laughter]
But things are tricky,
I get students coming
from Computer Science
and they want to do things
on causal inference
and it takes a huge amount
of effort to figure out
how they actually thinking
about problem
and whether there's something there
and so, now over the years,
I've got a little more appreciation
for the fact
that Don was actually willing to--
It took him a while,
but he did engage first with Josh
and then with both of us
and rather than dismissing
and say,
"Okay, well I can't figure out
what these guys are doing
and it's probably just
not really that interesting."
Everybody always wants
to figure out quickly,
you want to save time
and you want to save
your brain cells
for other things.
The fastest route to
that is to figure out
why you should dismiss something.
Yes.
I don't need to spend time on this.
♪ [music] ♪
- [Narrator] If you'd like
to watch more
Nobel conversations, click here,
or if you'd like to learn
more about econometrics,
check out Josh's "Mastering
Econometrics" series.
If you'd like to learn more
about Guido, Josh, and Isaiah
check out the links
in the description.
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