
In addition to publishing best-selling books about pregnancy and child-rearing, Emily Oster is a respected economist at Brown University. Over the course of the pandemic, she’s become the primary collector of data about Covid-19 in schools. Steve and Emily discuss how she became an advocate for school reopening, how economists think differently from the average person, and whether pregnant women really need to avoid coffee. This episode originally aired on February 26th, 2021.
Loading summary
Commercial Announcer
America's best network just got bigger. Switch to T Mobile today and get built in benefits the other guys leave out. Plus our 5 year price guarantee and now T Mobile is available in US Cellular stores. Best Mobile network based on analysis by Google of speed test intelligence data 2H 2025 bigger network the combination of T Mobile's and US cellular network footprints will enhance the T Mobile network's coverage price guarantee on talk, text and data exclusions like taxes and fees apply. See t mobile.com for details.
Emily Oster
So good so good so good.
Nordstrom Rack Advertiser
New markdowns up to 70% off are at Nordstrom Rack stores now and that means so many new reasons to rack
Emily Oster
cause I always find something amazing.
Steve Levitt
Just so many good brands cause there's always something new.
Nordstrom Rack Advertiser
Join the Nordy Club to unlock exclusive discounts. Shop new arrivals first and more. Plus buy online and pick up at your favorite Rack store for free. Great brands, great prices. That's why you rack.
Interviewer (Steve Levitt)
Emily Oster is not only a leading academic economist tenured at Brown University, but also, through her popular writing, one of the most trusted sources on the subject of pregnancy and childrearing. And over the last year she's been an early and influential voice advocating for school reopening. I often say economics is just the thoughtful application of common sense, and Emily, more than just about anyone else I know, has found ways to take what is useful about economics and integrate it into all aspects of her everyday life. And she's been doing that since a very tender age. When she was only nine years old, she started a weekly newsletter for the residents of her block, replete with data analysis, pie charts and graphs. And even before that, As a precocious 2 year old, her nighttime ramblings lying alone in bed were so remarkable they were tape recorded and analyzed, resulting in a book called Narratives from the Crib, which is still in print Today, more than 30 years later now with an introduction written by Emily Oster herself.
Steve Levitt
Welcome to people I mostly admire with Steve Levitt.
Interviewer (Steve Levitt)
I first met Emily Oster almost 20 years ago. I was visiting the Harvard Economics Department for a day to give a lecture to the economics faculty, and as is customary with such visits, the remainder of your day is filled in with one on one meetings with faculty members, and sometimes they fill in the slots with the most promising graduate students. As I looked over my schedule that day, there was only one name I didn't recognize. Who is this Emily Oster? I asked. One of your star PhD candidates? The organizer responded, well, actually, she's one of our undergraduates, but I think you'll find it worth your time. And I have to say I was deeply perplexed until I met Emily and she began to describe her undergraduate thesis on the relationship between crop failures in the Middle Ages and the frequency of witch trials. It was like I was talking to a young version of myself, except that she was female and 10 times better than I was at her age, doing the weird sort of economics I always loved. I've been her biggest fan ever since. And you know what's so funny about the whole thing? I remember our meeting like it was yesterday, every detail. But Emily has no recollection of it at all. It's supposed to be the other way around when the hotshot professor meets with the undergraduate. Emily Oster. I'm so glad we're having the chance to talk today.
Emily Oster
I am really excited to get to talk too. Thanks for having me.
Interviewer (Steve Levitt)
So, as you well know, I think the academic research that you've done is mind blowing, but I'd like to start with your transition from being an academic economist to being an all purpose purveyor of thoughtful, well informed common sense. And I think that story begins when you were pregnant with your daughter and trying to make good choices.
Emily Oster
Yeah, I think that's roughly right. I've always been pretty interested in trying to communicate research and communicate the ideas of economics to the outside world, but I got much more interested in it when I got pregnant. I started thinking about using things that I was doing in my job, in my pregnancy and just trying to figure out what the data really said. And I got, I mean, obsessed and maybe a little strong, but yeah, like a little bit obsessed.
Interviewer (Steve Levitt)
And you were disappointed in the advice that was available to expectant mothers?
Emily Oster
I found the way that many of the pregnancy books were written and much of the advice that I was given to be basically pretty patronizing. It was in a space of either just don't do anything and don't think about it for yourself or, or oh, everything is going to be fine little girl like Pat, Pat on the head. Just listen to the doctors. That didn't work for me.
Interviewer (Steve Levitt)
And so you decided in the midst of all your academic success, but still young and untenured, to do something that many people would perceive as crazy. And that you decided to write a book for a non academic audience on pregnancy even though you're an economist. And that book of course was called Expecting Better. Did you not think that was career suicide?
Emily Oster
I basically didn't think that much about it. I had been doing some of this research and doing some writing and I really liked doing the writing. I thought it was really fun. And on a total whim, I sent a book proposal to Suzanne Gluck, who is your agent and is now my
Interviewer (Steve Levitt)
agent, and who's been on this podcast, by the way.
Emily Oster
And I sent it to her and I said, you know, I've been working on this. So she wrote back and was like, this is great. Well, I have a few comments. We'll send it out. And now that I know more about publishing, I realize how bizarre and lucky that was. But I thought at the time that I could pitch it as like, it's a hobby. I'm also doing my academic work, and this is a thing I do on the side, like windsurfing or something.
Interviewer (Steve Levitt)
You're not allowed to have hobbies when you're an academic. I mean, you have to pretend you don't have hobbies, even though we all do. So just let me describe the book for people. You come at it admittedly as an outsider, and you don't pretend to have any particular knowledge. You just say, hey, I'm going to look for the research that meets basic thresholds, and I'm going to look at those as an educated data scientist and tell you, a woman, what they say, and then you get to make your own decisions, given the evidence and what the costs and the benefits are around it. I think the strength of the book to me was that you come off as being very believable because you don't seem to have any agenda at all.
Emily Oster
Yeah, I think the agenda was to try to figure out what was the good research. I mean, sometimes people ask, what's a book like? And I say, well, it's something between a memoir and a meta analysis. There's a piece that's about my personal journey in this. But then a lot of the book is like, here are a bunch of papers on this. Here's how you can wade through this literature and understand what it really says. And you're capable of really looking at this data and making these decisions for yourself. And you don't have to trust me as some expertise, except that I'm an expert in telling you what the data says, but I'm not an expert in what you should do.
Interviewer (Steve Levitt)
So could you just give us one example? One of the topics.
Emily Oster
So women are told to restrict their coffee intake or not have any coffee. The advice varies, and the idea is that it could increase the risk of miscarriage. I asked the question both what does the data really say? And also, why do people disagree? Which I think is Important for people to understand. If you compare women who drink coffee to women who don't at some pretty high level of coffee drinking, you will see an observational link with miscarriage. But it is also true that the women who drink coffee are very different on a bunch of other dimensions, most notably age, which is also correlated with miscarriage. So it's hard to know if it's age or coffee drinking. Coffee drinking is also negatively correlated with nausea. So women who are nauseous tend to drink less coffee, but nausea is also associated with a decreased risk of miscarriage. So as you add controls for age for nausea, you get weaker and weaker correlations, trending towards zero, and in many cases actually being zero.
Interviewer (Steve Levitt)
So let me just make sure I understand. If you just look at raw data, not trying to take anything else into account, what you see is that there is a positive relationship between caffeine consumption and miscarriage. And then as people are more careful and they start to say, oh, well, older women drink more coffee and they have more miscarriages, let's try to compare older women to older women and different variations on that. What you're saying is that the correlation you see in the data changes to become weaker and weaker. So from that you conclude that probably the sensible thing is to drink maybe not infinite amounts of coffee, but not to worry about it very much.
Emily Oster
That is correct.
Interviewer (Steve Levitt)
And so that's just an example of logic. And you do that for every topic, and you do it in a way that brings a lot of reassurance to people. And it's interesting because I think part of the reassurance comes because you're an outsider and you haven't done any of this research. You don't have any stake in it, and so you feel like an honest purveyor of the truth.
Emily Oster
I actually have come over time to also think the fact that I was doing this in the service of my own pregnancy and that I talked through how I thought about some of these choices has made the book more accessible to people and made them more comfortable because they feel like I'm their friend, which I am happy to be anybody's friend.
Interviewer (Steve Levitt)
So Crib Cheat, which is your second book about child rearing, is very much in the same spirit as Expecting Better, but in many ways I think harder to write because the data are not nearly as extensive or as conclusive on child rearing as they are on pregnancy. So how did you deal with that?
Emily Oster
When I came into writing Crib Sheet, I thought it would be much more like expecting better, where it would be just grinding through a lot of papers and there's a piece of that. But then it also becomes clear as you do this that actually a lot of what you conclude at the end of extensively researching a topic in early parenting probably doesn't matter too much in the long term. And that meant that in the end, much of the message of crib sheet is actually there's a lot of good ways to, to parent and you really need to pick the things that are going to work for you and your family.
Interviewer (Steve Levitt)
Can we talk about breastfeeding? Because I think that's such an interesting debate. As my wife was facing the choice of breastfeeding or not, she had been completely and utterly convinced by the public discussion that she would be an awful, awful parent if breastfeeding didn't work out.
Emily Oster
The public pressure that people are putting on themselves, on each other about breastfeeding is, as you say, it's so far beyond anything that could even be supported by science. I read some article at some point that said breastfeeding will help you form better friendships. What would that even mean? It's become such a cult thing. And I think that the downside of that is that if it doesn't work or it's not for you, or you don't like it, or you want to quit, it's like, well, don't you love your baby? And then people feel terrible.
Interviewer (Steve Levitt)
Yeah, absolutely. So just for the record, let's just talk about what the science says about breastfeeding. Because there's this mythology about it and then there's the actual facts.
Emily Oster
When you dig into the science, you find that breastfeeding has some benefits to digestion early on in life. So in particular for babies who are a few weeks old in the first year, maybe even there are some lower gastrointestinal risks, maybe a slightly lower risk of ear infection, that's a little weaker. There are some also digestive benefits for very preterm babies. And there's actually some evidence of a breast cancer risk reduction for the mom, not for the baby. But all of the kinds of things that your wife was hearing about and I heard about around your kid will be smarter and thinner and they'll be able to fly and they're going to have all these long term life health benefits. Those things are just not supported in the data.
Interviewer (Steve Levitt)
And how about iq? What's the evidence on iq?
Emily Oster
No, not iq.
Interviewer (Steve Levitt)
Zero, right? Zero.
Emily Oster
No, zero.
Interviewer (Steve Levitt)
So you're happily going along an academic who's writing these popular books and now it's March 2020. What happens because you've been writing these pieces on what if your kid can't poop and you really suddenly change course.
Emily Oster
My publisher said you should really have a newsletter. I started in January 2020 and I had this image that this was going to be just an occasional thing to connect with the readers. And then when Covid started, all of the questions I got were just things about COVID and Covid and Covid. And I started writing a lot about COVID both around some of the pieces of data on how risky is it for your kids and. And then also much more on decision making and trying to help people think through some of these decisions that they had never thought that they would need to make, particularly around parenting. Should I see the grandparents? Should I send my kid to daycare? And then it sort of evolved into studying daycares in schools.
Interviewer (Steve Levitt)
So I think you've developed a framework for making sensible decisions in settings in which you don't have great information. Do you want to describe a little bit how you think about decision making?
Emily Oster
Economists talk a lot about trading off risks and benefits, which is a big piece of decision making. But when I outlined this for people, I made the point, you need to start by framing the question you are asking. And so particularly when there's so much uncertainty and the decision is so new, I think that people very frequently, they know what the first option is and then they frame the second option as or not, should I send my kid to daycare or not, but or not is actually not an option, or not is some other thing. And this choice is going to be really different. If it's, should I send my kids to daycare or hire a full time nanny? Should I send my kids to daycare or have my elderly parents take care of them? Should I send my kids to daycare or quit my job? And then I tell people, look, you need to end your decision by making a final decision. Rather than what I think a lot of people do, which is just keep thinking about it over and over again and allowing it to take over. Every time they're in the shower, every five minute conversation with their spouse, every little moment you really want to say, okay, we're going to make the decision and then we're going to try to move on.
Interviewer (Steve Levitt)
So you have this decision framework, but somehow or another you went from that into being a creator of data. How did that happen?
Emily Oster
I mean, who knows? I really like data and I started to get just very frustrated at the lack of data around kids and particularly around kids in childcare and like to Be totally frank. My children were at my house all the time and I was eager to dispense with them to an outside location. I just put up a Google form in my newsletter. I had by the end of it like 100,000 kids, or the COVID rates are like about a tenth of 1%, which I think turned out to be very, very close to what other people ultimately found in better data.
Interviewer (Steve Levitt)
And you go from there to what I think is a really unlikely step of becoming the central collector and keeper of data on kids in school and Covid for the entire US. I mean, God bless you for doing it, but how did that happen?
Emily Oster
As a result of this childcare stuff, I started writing more about schools and what it would take to open schools. And then at some point, somebody connected me to a data processing company and to the School Superintendents Association. In the end of September, we published some Data on like 200,000 in person students. So a very, very small number of kids. But then of course, nobody had any data on Covid cases in schools. And then some states started doing some things that were useful and helping us a little bit. And so then we became this aggregator,
Interviewer (Steve Levitt)
source, I should have said. This is called the COVID School Dashboard.
Emily Oster
Yes.
Interviewer (Steve Levitt)
So what have you found?
Emily Oster
Basically, the rates in schools are low. They mimic community rates. But I think relative to some of the fears that people had in the summer, that schools were going to be super spreaders and giant Covid sources, that isn't showing up in the data.
Interviewer (Steve Levitt)
And is there a difference between the positive rates for the students and the teachers?
Emily Oster
Definitely. So you see higher rates in teachers in staff than in students. And, you know, that is almost certainly reflecting at least in large part the fact that staff are older. And in general, people who are older tend to get Covid at higher rates than people who are younger. So kids just have very low rates.
Interviewer (Steve Levitt)
So I have to admit I find your results surprising because I would just think kids aren't necessarily that great at keeping their masks on and they sneeze a lot. I would have expected more spreading. Do you or anyone else have a good idea why schools aren't spreading as much as we might have thought?
Emily Oster
I think your instinct is an instinct many of us had early. I think it's been a hard thing to push out of our minds because kids are generally pretty high risk for viruses like this. But for whatever reason, kids are much, much less likely to get Covid, particularly little kids. I think the other thing is that a lot of schools that have been open are pretty controlled environments. People are wearing masks, they're anxious in school, which is of course in some ways bad, but also means that they're being a little bit more careful than they would be otherwise, particularly the adults.
Interviewer (Steve Levitt)
The other side of the coin is that in deciding whether to reopen schools, it depends on exactly how terrible remote schooling turns out to be. What does the evidence look like in that dimension?
Emily Oster
Remote schooling has been really terrible for people. A lot of kids are just not logging on and so you can't teach kids if they are not there. Another thing is that it's just hard for little kids in particular to focus on zoom. The other thing is that kids are really struggling emotionally being out of school. And so we've seen learning losses, we've seen increased failure rates, we've seen more reports of anxiety and depression and weight gain and all of those auxiliary add on effects.
Interviewer (Steve Levitt)
So the weight of the evidence, based on what you're seeing of relatively low transmission rates, big costs of remote schooling have led you to transition away from being a data collector to really being an advocate for reopening school. Is that a fair characterization of your position?
Emily Oster
Yeah, I think that's fair. I think I came into this conversation really wanting to see what the data said, understanding that there were likely to be learning losses. I think nobody anticipated how large they would be.
Interviewer (Steve Levitt)
And how does it feel?
Emily Oster
I hate it. I am doing it because I think it is important for kids and because I think it matters.
Steve Levitt
You're listening to people I mostly admire with Steve Levitt and his conversation with economist Emily Oster.
Shopify Advertiser
When it's time to scale your business, it's time for Shopify. Get everything you need to grow the way you want. Like all the way. Stack more sales with the best converting checkout on the planet. Track your cha chings from every channel right in one spot and turn real time reporting into big time opportunities. Take your business to a whole new level. Switch to Shopify. Start your free trial today.
Apple Card Advertiser
This message is brought to you by Apple Card. Apple Card members can earn unlimited daily cash back on everyday purchases wherever they shop. This means you could be earning daily cash on just about anything, like a slice of pizza from your local pizza place or a latte from the corner coffee shop. Apply for Apple Card in the Wallet app to see your credit limit offer in minutes subject to credit approval. Apple Card issued by Goldman Sachs Bank USA Salt Lake City Branch terms and
Nordstrom Advertiser
more@applecard.com this episode is brought to you by Nordstrom. Ready to refresh your wardrobe? Nordstrom has all the latest styles for spring. From elevated dresses and denim to standout tops and accessories, Discover the trends and essentials you'll reach for again and again. We've got brands you love like Waif, Princess, Polly, Mango, Adidas, and Favorite Daughter. Plus free shipping, free returns, and quick order pickup. Make updating your closet effortless. Shop in stores@nordstrom.com or download our app.
Interviewer (Steve Levitt)
So, to put it mildly, not everyone has been such a fan of your Covid efforts. But let me ask you a question. People can be unhappy with you because there's disagreements about what the data say. So one person's data says one thing and one person's data says another thing, or everyone can agree on what the data say but differ in the interpretation of the data. On this particular issue, do you have a sense of whether the disagreement is about the data or about the interpretation or about both?
Emily Oster
I think it's a little bit of both. I think early on people saying, look, this is an entirely opt in sample. And that was initially true. That's definitely no longer true. And then I think that, you know, the conversation shifted a little bit to, well, how can we be sure that there isn't some additional risk to staff? And you can't be sure about that from our data or probably from any data. And I think that there's some difference in what we should conclude based on what we see in the data. So if we thought that being a teacher had similar risks to the population or slightly higher risk, like, how should we think about decision making there? And I think that is a piece where there was some disagreement.
Interviewer (Steve Levitt)
I almost wonder whether maybe a partial solution isn't something like combat pay where just like with soldiers, because of some extra risk that we're putting on teachers, maybe we should be compensating them for that risk.
Emily Oster
That's certainly something that people raised at the beginning. I mean, I think we also want to be clear that, like, the added risk of teaching in person in a school is probably substantially less than the added risk of working in a grocery store or driving an Uber or working in a restaurant. There's a reasonable view that all essential work should effectively have combat pay in this environment. And I think that you could view some of the prioritization of teachers in vaccines as a version of that thing. I think they should be the front of the vaccine line. Teachers are an easy group to reach. We know where to find them. They tend to be very socially engaged. If they are vaccinated, I think they will be great advocates for vaccination in particularly underserved communities. I think that because they're out in the world, they are at more risk than someone who is literally not out at all. And also I think that in some places teacher vaccination is going to be a prerequisite to get kids back in school.
Interviewer (Steve Levitt)
So I've tried to read the things that are critical of you in this area and it seems like maybe the worst critique that's been leveled at you is people claim that you downplay evidence that doesn't support your position, which is actually what advocates do all the time. You have to have a simple message and you can't offer the nuanced messages that you've offered. Always been putting forth before is more of an outsider looking in. Do you feel any conflict in being an advocate?
Emily Oster
It's an interesting question. I think there is a piece of that in advocacy where you want to be in some ways more critical of the pieces that disagree with you versus the pieces that agree. And you know, I've tried to take off my advocacy hat when I'm thinking about things that disagree.
Interviewer (Steve Levitt)
So obviously we're operating in a really data poor environment when we're making decisions about COVID Even despite of your own efforts to try to increase the flow of data. And I wonder whether in your own books the kind of evidence we have about COVID wouldn't meet the standards that you would hold studies up to make these hard choices. Now, I understand we have to make choices here. Do you have any misgivings in light of that?
Emily Oster
Not really, because of the last thing that you said, which is that I think that we have to make a choice. People have been thinking about it like, well, let's just be safe and not open schools. And until the data is perfect and we're 100% sure that we know exactly how to make sure there's no transmission in schools, let's just keep them closed. But the thing is that we cannot afford to make decisions like that in this current environment because every day that kids are not in school, they are losing. And so there's no safe great option here. We're gonna have to make a choice with imperfect data. For me, that's been a hallmark of all of the aspects of the pandemic is we're making all of these choices with not very good data and we're just trying to make the best choices that we can and the choices that minimize harm.
Interviewer (Steve Levitt)
You've had so many interesting academic research findings. Maybe we could start with one of your newer studies which demonstrates the self fulfilling prophecy of health fads could you explain that.
Emily Oster
I think it's easiest to explain this by starting with just an example. Let's say that some researchers are researching what kinds of foods improve longevity. And they run a bunch of things and they come up with pineapples. Pineapples increase your longevity. And let's just like imagine that's a false positive. Right?
Interviewer (Steve Levitt)
So they make a mistake.
Emily Oster
They make a mistake, yeah, but they
Interviewer (Steve Levitt)
get a New York Times and a Washington Post headline that says, pineapples are the secret to a long life.
Emily Oster
Exactly. And so then you think about what happens. Maybe on average everybody eats a little more pineapple. But it's particularly the people who are like reading the New York Times to find out what food they should eat to make themselves live longer. It's like my dad, this paper is totally inspired by my dad who adopts every weird food health fad that the New York Times says that he should do. And of course those people are also doing all kinds of other stuff. They're also not smoking and they tend to be better educated and they're running all the time. And so then if you said, okay, let me go back and let me take a look at this pineapple thing again with more new data now actually you've created a situation where pineapples are even more strongly associated with living a long time because of the people who have started eating them.
Interviewer (Steve Levitt)
So just to make sure that people understand. So the first go round, the researchers made the mistake. They just looked at a bunch of people and they happened to see the people who ate more pineapple happened to live longer. But we've posited that was just by accident. But then what happens is people like your dad now become daily consumers of pineapple. And so they look three years later and say, well, let's just see if our theory is still true. But now when you compare the people who eat pineapple to the people who don't eat pineapple, pineapple eaters are super healthy. Exercising, good eating, probiotic taking people, and all of the Cheetos eating soda drinking people, they haven't paid any attention. And so now the comparison is between a really healthy group of people and a really unhealthy group of people. And it's a magnified, any possible direct causal effect of the health intervention itself.
Emily Oster
Yeah, exactly. As you said, like at the beginning, a self fulfilling prophecy where when I tell people they should do something, then the selection of who does it changes and then you get potentially these magnified effects. And then the question was just, can you see that showing up in data and would it affect what we conclude? And so in this paper, I look at a few things, the most striking of which is vitamin E, where there was a period in the early 90s when people were told, like, eating vitamin E helps you live for a long time. And then at some point there was a new set of studies that were like, oh, just kidding, it kills you. So actually the second set were randomized studies. So there was some observational studies that said vitamin E is good for you, and then there were some randomized studies that were like, actually, too much of it will kill you. And so what you see is after the studies that say it's good for you, a bunch of people start taking it, but they're precisely better educated people who don't smoke, who exercise more, who eat a good diet, and then those people disadopt later. But what's really striking is you see in some of the data, for example, the links that you would estimate between vitamin E and mortality basically are created by the selection. So in this intermediate period of time when vitamin E is highly recommended, it looks like it prevents you from dying. But that's entirely because of the adoption patterns that we see after we make the recommendation.
Interviewer (Steve Levitt)
I love that, because to me, the best research is exactly this, where you take on a topic and the insight you come up with is completely obvious. And I understand it immediately and it makes sense to me, and I file it in my brain and I use it forever after. And I asked myself, why didn't I think of that? How could that never have been mentioned before? Those are hard to come up with, but you make it look easy. How do you come up with ideas like that?
Emily Oster
So that idea really came out of the books because I started thinking about, like, well, I'm telling people to do stuff and I wonder if they'll do stuff. And at some point, somebody asked me this crazy question that was like, are you worried that all babies will now be the same because everyone is doing the things that you tell them? It's like, no, I'm not worried about that.
Interviewer (Steve Levitt)
Well, I think what's interesting in that is oftentimes these really good ideas are just hanging in the air, right? So someone brought that up, and you could have just dismissed it, but you saw the kernel of what was obvious and subtle in it. That's the secret to my own research is I just live my life with my eyes open, always looking for things that are obvious but can't be seen. And when I very rarely latch onto one, I really hold on tight and I try and prove it.
Emily Oster
For me, that's like the best moment of doing research is when you have a picture and the picture is what you thought it would be. That's a cool moment.
Apple Card Advertiser
This message is brought to you by Apple Card. Apple Card members can earn unlimited daily cash back on everyday purchases wherever they shop. This means you could be earning daily cash on just about anything, like a slice of pizza from your local pizza place or a latte from the corner coffee shop. Apply for Apple Card in the Wallet app to see your credit limit offer in minutes. Subject to credit approval. Apple Card issued by Goldman Sachs Bank USA Salt Lake City Branch terms and more at applecard.com so good, so good, so good.
Nordstrom Rack Advertiser
New markdowns up to 70% off are at Nordstrom Rack stores now. And that means so many new reasons
Emily Oster
to rack because I always find something amazing.
Steve Levitt
Just so many good brands because there's always something new.
Nordstrom Rack Advertiser
Join the NordicLub to unlock exclusive discounts. Shop new arrivals first and more. Plus buy online and pick up at your favorite Rack Rack store for free. Great brands, great prices. That's why you rack.
Mark Riepe
This episode is brought to you by Charles Schwab. Is there a right time to sell a stock? Are you taking the right risks with your portfolio? Financial decisions can be tricky, and often your own cognitive and emotional biases can lead you astray. Financial Decoder, an original podcast from Charles Schwab, can help join host Mark Riepe as he offers practical solutions to help overcome the cognitive and emotional biases that may affect your investing decisions. Listen@schwab.com financialdecoder.
Interviewer (Steve Levitt)
You've also spent years researching the decisions people make around genetic testing when they're at risk for having dreadful genetic diseases like Huntington's disease. Could you describe that research agenda and what you found?
Emily Oster
I got into that by thinking about human capital theory. So human capital theory is how we understand different choices people make about what we call human capital, which would be things like their education or their job training choices, which is a very old idea in economics. And trying to think about whether people would invest less in their human capital, get less education, do less job training and things like that, if they knew that they would live a shorter amount of time. And so the sort of insight in this set of projects was to look at people who are at risk for this particular genetic disease, Huntington's disease, where the genetics is very simple. If you have one copy of the affected gene, you get the disease for sure. There's this genetic lottery, which is if you have a parent with the disease, there's a 50, 50 chance you get it.
Interviewer (Steve Levitt)
So another key about Huntington's disease is that it doesn't manifest itself until later
Emily Oster
in life, when it appears varies based on some aspects of the gene. So the most common onset time would be the 30s or even 40s, although it can have onset in childhood or it can be very late.
Interviewer (Steve Levitt)
So you were able to see choices people were making as a function of what they knew would happen later in their life. If they carried the gene, then they would expect a much shorter life expectancy, and you could see what investments they were making in school, on the job, training, et cetera. That was a starting point for your research. But actually, in the end, the thing that turned out to me to be much more interesting and much more challenging to economists was the fact that very few people who have Huntington's disease ever get tested, which doesn't fit well with simple economic theory.
Emily Oster
Before they had this test, they asked people, are you going to be interested in having this test? And people basically said, yes, like a lot of people said yes. And then once the test was available, nobody wanted it. It's a perfectly predictive genetic test. It'll either tell you're going to have it or not.
Interviewer (Steve Levitt)
And from a simple economic perspective, you think, well, if I know whether I have this gene or not, I'll make completely different investments over my life. Maybe my decision about whether to have kids, maybe whether to go to college, whether to smoke or smoke crack, might depend a lot on the outcome of this genetic test. Usually economists think when there's a test that provides lots of information and you can get it essentially for free, everybody would do it. But what percentage of the people in your sample actually do get the test as teens?
Emily Oster
So of these people who have a parent with the disease, 5% of them get this test. It's very small.
Interviewer (Steve Levitt)
A strong economic prediction would be that everybody would get this test, or almost everybody. And yet our simple models are completely wrong. What do you replace our models with?
Emily Oster
When we started working on this question, what I wanted to understand was, how can we understand this behavior? Is it that people don't know about the test? The test is expensive, something about insurance. And none of those things were consistent with the data. And we actually had some data where we asked people, why don't you want to get this test? And the answer was, I don't want to know. But it started us down the road of thinking, well, maybe there is something deeper to the I don't want to know. We started thinking about models or mathematical formulations where people get value from what they expect to happen in the future. And in particular, they get value from imagining what's going to happen in the future. The basic idea is like, if I knew for sure that I was going to develop this terrible, debilitating disease later in life, I would have a hard time imagining that wasn't true. But if I don't know, then I can basically pretend that it's not a risk and I can have this anticipation of having a healthy, long life and that I may value that anticipation in a concrete way. So much so that I'm willing to not get the test.
Interviewer (Steve Levitt)
I've asked a handful of economists about this, and I've asked far more non economists. And what is so interesting is that every economist immediately says, of course I would get the test. And literally every non economist I've ever asked has said, I would never get the test. And it's completely obvious to them, it seems, at least the way I describe it, that they wouldn't really want to have the test. And there are a handful of other issues where I've run into the same thing, I think a market for organs where people could buy and sell their organs. I think almost all economists are in favor of such a thing, and almost all non economists are against it. It's always interesting and surprising to me to see that there is this really sharp distinction between people who are economists and people who are not.
Emily Oster
When I explain this to people who are not economists, they're like, of course nobody would want to know. Like, why would you even ever think anybody would want to know this information? Well, the theory said.
Commercial Announcer
So.
Interviewer (Steve Levitt)
You've had these many wonderful, remarkable papers, and then you also had one giant misstep where one of your findings ultimately didn't turn out to hold up. Would you be willing to talk about that?
Emily Oster
This whole thing is your fault. So I think it's just at the front. Let's just say I know everything we're about to say is 100% your fault. Okay?
Interviewer (Steve Levitt)
God, okay. And I'll take lots of responsibility. So I was indeed the editor at the Journal of Political Economy at the time, and I handled your paper. I absolutely will take some fair share of the blame, but. So just describe what the paper tried to do.
Emily Oster
In the beginning, there was this existing body of literature, most prominently popularized by Marchesen, noting that there are more men than women in a number of Asian countries, which are known for gender bias. And this is traditionally attributed to neglect of female children or sex, selective abortion in some cases.
Interviewer (Steve Levitt)
And we're Talking about a huge number, 100 million missing women. And the basic conclusion at that time was that they're missing either because of sex selected abortion, or of increased mortality rates along the way because of neglect by parents, essentially.
Emily Oster
Yeah, exactly.
Interviewer (Steve Levitt)
You had a different theory.
Emily Oster
I had a different theory based on having read a book and some science data. And my theory was that high rates of hepatitis B in these countries was contributing to some of this gender gap. And the idea was that women with hepatitis B were more likely to have male children, perhaps because of some aspect of interactions in the womb, and that was driving differences in the gender ratio. And that particularly in China, where hepatitis B carry rates are very high, that that might actually explain principle, quite a lot of these missing women, like half of them or something.
Interviewer (Steve Levitt)
Just to be clear, there was scientific evidence that suggested this might be true. And your role really was to take that scientific theory and try to quantify it by going to data that existed. You did that in a number of very imperfect data sets, but the best that we had, and you found really surprising and compelling evidence that, that it was important. And I found that Evans very convincing. And I eventually published her paper. And then people started looking at better data.
Emily Oster
As you said, the sort of data sources that I was using I thought were compelling, but were imperfect. And then at some point after the paper was published, some people got access to really like excellent data on this, which had actual testing results, and they found basically no effect of being a hepatitis B carrier on the child gender.
Interviewer (Steve Levitt)
I remember asking you, I said, what would be the definitive data source? And you basically designed something which would be the definitive study, knowing that most likely it was probably going to go against you, because the better data had supported the other side of the story. And I really admired the fact that you went and invested years of your life to go and find the truth, even knowing going in the truth was probably going to work against your initial hypothesis. Indeed, in the end, it did.
Emily Oster
Of course, I hoped that I would turn out to be right, but given what we knew at the time, it did seem likely that what we would find was that we were not. And, you know, I went to China, I collected a ton of data, went around to a lot of places in China and talked to people and got the data from registry books. And then, yes, in the end I was not right.
Interviewer (Steve Levitt)
And you wrote it up, frankly and honestly, and you crushed your original paper in the process. And while that is how science is supposed to work, I literally cannot think of another example in economics of that ever happening. You know, what makes me really mad is the fact that our profession should have cheered you on and should have canonized you for being a great scholar. But the only thing people wanted to talk about was how you really blew it on hepatitis B. So I just want to go on record as saying I think what you did was, was awesome. And I'm so disappointed that not that many people have recognized that you just did the right thing.
Emily Oster
That's nice. Thanks. Things turned out okay, and it was an important learning experience, I think for me. You know, I think if I had been a more mature scholar, I probably would have tried to get that data first before I published. We get more cautious as we age. Maybe.
Interviewer (Steve Levitt)
So within the economics profession, I get the feeling that a lot of people don't like you. Just like a lot of people don't like me. And I think that there's a lot of similarities in the way you and I approach the world. But do you also have the feeling a lot of people don't like you?
Emily Oster
Oh, definitely. Yeah.
Interviewer (Steve Levitt)
I have to be honest, while in general I'm almost oblivious to most gender based arguments, I have the feeling that you've had a harder time in economics because you were a woman and that you really have come out with strong opinions on important questions. And I'm sad to say, I think that your being a woman is part of why people have had a hard time accepting some of what you've said. Do you have any sense of that being true?
Emily Oster
There may be some gender disadvantages. I think there are other ways in which I'm tremendously like advantage. Right. My parents are PhD economists, and so in those ways I feel very lucky. Economics is a weird. It's a very gendered place. There are a lot of women who have really awful stories about what it is like to be a female economist. And I have a few of them too. I think it's not just that I'm a woman, but I am a woman who is prominently discussing vaginas. And that's not just in my books. I mean, I once wrote a paper about menstrual cups in Nepal. A menstrual cup is a reusable cup that you use during menstruation. And when I gave talks about that, I would bring a menstrual cup to the talk and pass it around. There's a being a woman and then there's not being apologetic for it. And I think that's not to everybody's taste.
Interviewer (Steve Levitt)
Do you have any advice for people who find themselves in the middle of a Big public fight.
Emily Oster
Try not to take it so personally. That's my personal advice to myself. I think part of what's made this advocacy position, particularly around schools, so unpleasant for me, is that I take everything, like, really, really, really personally. It's like when you read your teaching ratings, when everyone's like, oh, you're an amazing teacher. And then the one guy is like, this class sucked, but you're in a public fight. There's a lot of guys who are like that guy.
Interviewer (Steve Levitt)
What about emerging with your reputation intact or well liked or respected? Do you have advice about that?
Emily Oster
Try to be honest, and try to be honest when there are limitations. And that's hard, as we said, you move into doing more advocacy, it becomes more difficult to keep that. But I think that at the end of any public fight, it's certainly for someone like me, where I hope that I will stop doing this stuff on schools and they will all open and I can go back to, you know, writing about Juice. I want to come out of that knowing that I feel comfortable about what I did with me and that I'm the person I ultimately have to live with and my husband. And I guess,
Interviewer (Steve Levitt)
believe it or not, in 25 years, I have never read my own teaching evaluations. I won a teaching award the very first time I taught, which I took as evidence that I was a naturally born amazing teacher. And ever since then, I've been terrified to look at my teaching evaluations because what if it's not true? Well, at one level, I know it's not true.
Emily Oster
True.
Interviewer (Steve Levitt)
It's been 25 years since I won a teaching award, and that's pretty solid evidence that I'm not quite the teacher I imagine myself to be. In the end, when it comes to teacher evaluations, I guess I'm just like the people Emily Oster studied who chose not to take the genetic test to determine whether they carried the gene for Huntington's disease. Sometimes ignorance is bliss, even when the economic models tell us otherwise.
Steve Levitt
People I mostly admire is part of the Freakonomics Radio Network, which is produced by Freakonomics Radio. Morgan Levy is our producer and Dan Dezulla is the engineer. We had help on this episode from James Foster. All of the music you heard on the the show was composed by Luis Guerra. We can be reached@pimareekonomics.com that's P I M A Freakonomics.com. thanks for listening.
Emily Oster
Maybe we're jerks.
Interviewer (Steve Levitt)
Yeah, we might be jerks.
Steve Levitt
Foreignomics Radio Network the Hidden side of Everything
Commercial Announcer
hey, it's Dan Cummins. If you're into the weird, the wild, and the downright bizarre, check out my podcast, timesuck. Each week I dive into shocking stories like the rise of the Nexium cult, the origins of conspiracies like QAnon, and the San Francisco Witch Killer murders. With deep dives and dark humor, Time Suck brings you the stories that'll fascinate you, make you laugh, and fill your head with lots of strange facts. New episodes drop every Monday. Join the Cult of the Curious. Follow Time Suck wherever you get your podcasts. And Doug, there's nowhere I wouldn't go to help someone customize and save on car insurance with Liberty Mutual. Even if it means sitting front row at a comedy show.
Emily Oster
Hey, everyone, check out this guy and his bird. What is this, your first date?
Commercial Announcer
Oh, no. We help people customize and save on car insurance with liberal Liberty Mutual. Together. We're married. Me to a human, him to a bird.
Emily Oster
Yeah, the bird looks out of your league.
Commercial Announcer
Anyways, only pay for what you need@libertymutual.com
Angie Hicks
Liberty Liberty Liberty Liberty hi, I'm Angie Hicks, co founder of angie, and one thing I've learned is that you buy a house, but you make it a home. Because with every fix, update and renovation, it becomes a little more your own. So you need all your jobs done well. For nearly 30 years, Angie has helped millions of homeowners hire skilled pros for the projects that matter, from plumbing to electrical roof repair to deck upgrades. So leave it to the pros who will get your jobs done well. Angie. The one you trust to find the ones you trust. Find a pro for your project at Angie. Combination.
Podcast: People I (Mostly) Admire
Host: Steve Levitt (Freakonomics Radio + Stitcher)
Guest: Emily Oster
Episode: 17
Date: April 11, 2026
This episode features economist, author, and data communicator Emily Oster, interviewed by Steve Levitt. They explore Oster’s journey from academic economist to bestselling author and public advocate, delving into her approach to data-driven parenting advice, her influential role in the COVID school reopening debate, and the complexities of balancing advocacy with scientific integrity. Oster’s candid reflections on gender, professional risks, and her most memorable research victories and failures offer an honest and insightful portrait of a scholar who is unafraid to challenge consensus and stand in the public eye.
Early Passion for Data
Academic Beginnings
Motivation and Method
Coffee and Pregnancy: Unpacking the Evidence ([07:05])
Breastfeeding: Science vs. Social Pressure ([10:13])
Pivot to Pandemic Advice ([12:11])
Decision-Making Frameworks in Uncertainty ([13:06])
COVID School Dashboard ([16:01])
The Case for Reopening Schools ([17:32])
Public Pushback ([20:36])
On Advocacy vs. Objectivity ([22:44])
Making Decisions with Imperfect Evidence ([23:33])
The Pineapple Effect ([24:51])
Finding Inspiration
Handling Criticism ([42:25])
Maintaining Integrity ([43:06])
Levitt’s Own Caution
This episode is a rich, candid exploration of what it means to bring economics to the real world, embrace data-driven nuance, admit mistakes, and stay grounded through controversy—all in Oster’s characteristic blend of rigor, relatability, and wit.