Pushing New Ideas (Guido Imbens, Josh Angrist, Isaiah Andrews)

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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 the research
was initially received

and how they responded
to criticism.

At the time, did you feel like
you are on to something,

you felt like 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--"

We proved something be proved up
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 but that
took longer than I think you remember.

Yeah, 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--

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, did you

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 metricians,

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 more vocally against that,

that never really bothered me that much.

It seems clear that we had a result there

and it was 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, 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] But 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.

Yeah.

But it's a 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.

For quite a few years, we had to sell

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 [learned] 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.

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,

"Wow, but here you thinking of it this way,"

but that's actually a pretty hard thing to do,

get someone from a different discipline,
convincing them,

two junior faculty in a different department
actually have something to say to you,

that's that takes a fair amount of effort.

Yeah, I wrote on 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 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 wounded serve in
the military irrespective of

whether they were getting drafted

and you and Don said something
about shooting yourself in the foot,

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 would say,

"Well, yes you could do that
but why would you want to shoot yourself in the foot?"

[laughter]

It got a little [inaudible] there.

I usually go for moving to Canada for my example
when I'm teaching that.

But he thinks it's 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,

"Well, okay I can't figure out what these guys are
doing and it's probably just not really that

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.

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- [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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