Hi. I’m thrilled to be interviewing Emily Oster, PhD, who’s a professor of economics at Brown University. She’s the best-selling author of Expecting Better: Why the Conventional Pregnancy Wisdom Is Wrong–and What You Really Need to Know and her latest book, which is Cribsheet: A Data-Driven Guide to Better, More Relaxed Parenting, from Birth to Preschool. Her work has been featured in The New York Times, The Wall Street Journal,Forbes, New York, and Esquire among other publications. Emily received her BA and PhD from Harvard, so she’s a total moron. She currently lives in Boston with her husband, also an economist, and their two children.

Thanks for coming on “Moms Don’t Have Time to Read Books.”

Emily Oster: Thank you for having me.

Zibby: It’s such a thrill to be able to talk to you. I feel like you’ve become such a guru on all things parenting from such a thoughtful place. I get my personal dose of expertise this morning, so thanks. Can you tell listeners what Cribsheet is about?

Emily: Cribsheet is about parenting. It’s about using evidence to make parenting choices. It’s about breastfeeding and vaccinations and sleep training and co-sleeping, and all the big things that come up in the first few years of life and also some of the smaller things that come up, and really about looking at what does the evidence say about these choices? There’s a lot of noise that we get when we are thinking about these choices from people who want to give advice. Some of the advice is well-meaning. Some of the advice is bossy and mean. Some of it’s somewhere in between that. This book is really about saying what does the actual evidence say about those choices? How should you think about making the choice that works for you since in a lot of these settings, it is not obvious from the data what is the right thing to do. There aren’t that many places where it’s like, “You should definitely do this. You should definitely not do this.” There are a few, but not that many. Much of the work of the book is to really say here’s the evidence. Now, how should you make this choice?

Zibby: When I was talking to our mutual friend Anna who’s also an economist, she said, “I reviewed all this literature, but it never occurred to me to write a book about it.” What made you not only review all the literature, I am assuming for your own kids, but then take it for the benefit of everybody else?

Emily: This started when I wrote about pregnancy. My first book is a similar approach to pregnancy. I had a reaction. I said that because a lot of economists have told me this, and not just economists, but lady academics have said, “I did a lot of this research, but I never thought about writing it down.” Part of it is that I really like the process of trying to write for a broader audience and thinking about the challenges that come with that kind of writing in a way that’s different than the challenges that come with academic writing. I was always more predisposed to that. The other way to say it is I took this a little far. I was one of these people who was like, “I should write a book about that,” but then I did it. There it is. The second book came out of the first book.

Zibby: I love that there’s a way you found to actually spin that as some sort of a negative, that you took it too far. You’re this super accomplished person with these great books. You’re like, “Oh, I couldn’t cut myself off.”

Emily: I took it too far, too much.

Zibby: How did you even end up becoming an economist? Let’s start there. I know both of your parents are economists.

Emily: Both of my parents are economists. I knew that was a job that one could have. Actually, I wanted to be a scientist or a doctor, which I think is not inconsistent with where I’ve ended up. In college, I was very into biology. I got this job after freshman year working in a fruit fly lab. Actually, I had two jobs. One job was on the side. I was doing some economics research for somebody that I had met through my parents. Then I was also working in this fruit fly lab. I realized that I hated working in the fruit fly lab. More than not liking it, I really do not have the temperament for wet work in a lab. This was not something I turned out to be passionate about. I really liked the economics stuff that I was doing. I veered into that. I’ve always really liked doing research. This was the kind of research that I got drawn to. Then I became an economist.

Zibby: For your mom to be an economist, I feel like there aren’t that many economists — not that I know too much about this — in that generation. She must have a really cool story.

Emily: Yes, my mom does have a cool story because she did not grow up with parents who are professors. Her mom was a waitress who didn’t finish high school and immigrated from Sweden. My mom went to college at Hofstra, which is not an especially good college, fine college, but she didn’t go to an Ivy League school. Then she was trying to decide, should she get a PhD in economics? Should she go to law school? She applied to Harvard and Yale for those things. The thing she got into was the Harvard Economics Department. Then she went there. There were two women. It was a different time, although not as different as we might wish. She ended up being an economist, which is very nice.

Zibby: You have this gift, obviously, for taking your economics hat and applying it to things that weren’t always so typical fodder for economists. Have you done this for other industries aside from parenting? Not that parenting’s an industry, but do you apply this lens anywhere else?

Emily: I apply this lens everywhere else in the scope of decisions that I make about my life. Part of it is my husband is also an economist. It’s a shared language. When we’re thinking about choices, even before we had kids, thinking about choices about what should we do with our time, or how should we shop for a house, or where should we live, all of these things are influenced by this approach that, to us, seems like that’s just how you make decisions. Then when you explain that to other people, they’re like, “You guys are crazy. You have a crazy relationship.”

Zibby: You showed an example of it in your book about ordering vegetarian meal kits, is where you ended up when you were debating how to cook. Can you take me through an example of how someone might approach a decision versus how would you approach a decision? Take something normal. I don’t know. Pick something, like how you decide what to do on a Saturday morning with your kids. How do you make the normal decisions that you have to make fifty-seven times a day?

Emily: We probably are not quite that crazy about the normal, everyday decisions. It’s more when it comes to decisions of how should we spend money? Should we outsource this thing? We make a lot of decisions about should we do this or should somebody else? Should we clean the house? Should someone else clean the house? Should we order meal kits? Should we do this? A lot of people make that choice by what do I want and what can I afford? In some ways, those are the central considerations for what we’re doing, but the language is different. It’s like, what’s the opportunity cost of my time as opposed to what we can afford, which are effectively a similar question but not exactly the same. Similarly, rather than saying what do I want, it’s what would be my willingness to pay to have somebody else do this? How much money would I accept to clean somebody else’s house? It’s a different way to frame that question that I think is not the way everyone would do it.

Zibby: Interesting. I love how you used marginal utility to describe — I think you described marginal utility in relation to how much time you can spend with your kids. I can’t even find this question that I wrote. After a while, like you spend an hour with your kids on the floor, is the second hour that much more important? I’m flashing back to my intro economics class with the graphs going down.

Emily: The graphs going down, exactly. Your marginal utility is diminishing. It’s diminishing. We teach this in economics classes around apples. The first apple is really great. After you’ve already had fifteen apples, that last apple doesn’t taste that good. This is an application of that to the idea of time. As you spend time with your kids, the marginal hours, the next hour is, for some of us, not as good as the first hour. When you think about the optimal time allocation, you have to compare the marginal hours, not the average hours. This is something I spend a lot of time on in class, the distinction between marginal and average. On average, I could enjoy my kids much more than my job. I could still prefer to spend more time at my job if the marginal utility is declining more slowly. That does not always go over well with everybody.

Zibby: With any unique point of views, it can’t go over well with everybody.

Emily: Some people are like, “Yes. That’s what I think.” For some people, that is an insight. “Yes, that’s a good way to explain how I feel about this decision.” For some other people, it’s not. That’s how I’m used to thinking about it.

Zibby: That’s how you — rationalize is the wrong word. You don’t need to rationalize or justify working. I feel like you said that, in an article for working parents, if the marginal utility is going down, then you might as well go do what you love.

Emily: Yeah. Rationalize is not the right word because it implies that somehow this choice is not the right choice or not a good choice or something. You’re right. It’s a way to understand that this is the choice that works for you. There is a cognitive dissonance between the idea that, “If I love my kids more than I love my job, then shouldn’t I be spending all my time with them?” Those two things are not implied by each other. When you think about this choice, deciding to go to work is not the same as saying you do not love your kids. Even for those of us who are very sure that we want to work, there is that dissonance. It helps to have thought about it.

Zibby: Now I am back to my intro to psychology class for cognitive dissonance. This is great. I’m going to get a refresher.

Emily: It’s a refresher of undergrad.

Zibby: I need you to dabble in art history for a few minutes. Then I’ll be covered. Cognitive dissonance, why don’t you explain that concept?

Emily: I’m not a psychology professor. The way that I understand this is that when you have made a choice, you don’t want to think things or do things that make that the wrong choice because that causes you to feel cognitively dissonant like somehow you have these two different things in your head. This actually comes up all the time in some of these big parenting choices. Even in something like breastfeeding, breastfeeding is a lot of work. If you want to breastfeed your kid until they’re a year old, that’s actually a fair amount of work. Some of what happens when we think about why people can get so militant about this is that after you’ve done all that work, you want it to be like it’s really important. You want to feel like this is the most important thing. Otherwise, why did I spend all that time doing it? That can lead us to then be interested in telling other people, “Obviously, this is so important. You should understand that because I spent all this time doing it.” It can be hard then to say, “I spent a bunch of time doing it because that was the choice that worked for me, but maybe it’s not the choice that works for everybody.”

Zibby: Thank you for that. You don’t have to teach anymore. You have all this data in your book and synthesize it in a really great way. What about just going with your preferences? Do you think now that you’ve given everybody the data, should people just wing it? Should people try to research it? Both?

Emily: There’s a piece of this where some people have said, “Is this book just go with your gut? Does this book just say, ‘Here’s all the data, but actually make whatever choice you want’?” There is a little bit of that feel sometimes because in many of these choices, the answer is there’s many good choices. You have to decide what works for you, which is a bit different, actually, than going with your gut. What I’m advocating here is that you take a structured approach to making the decision.

The structured approach involves looking at the data and then combining that with some actual understanding of your preferences, not what do I feel right this second, but what are the things that’s going to work for my family? You should talk about it with your spouse. You should have a plan. You should think about how do we see the costs and benefits here, which is different from saying going with your gut. It’s also different from saying that everyone should do the same thing. There’s a role for preferences, which is different from just knee-jerk, whatever you’re feeling in the moment kind of approach.

Zibby: Now that you’ve written all this stuff about parenting, do you put pressure on yourself when you’re dealing with the routine parenting issues like tantrums? I’m not sure how old your kids are now. All these things that happen in daily life, do you feel like, “Wait a minute. I should be able to control this. I research this. I know this”? Is there some funny thing that happens to you in your exact position?

Emily: The place that I really feel this is sometimes when I’m in public. Of course, it’s not like people know who I am. It’s all an internal thing. There was a time not that long ago we were in the airport. My son was licking the escalator. I was like, “Oh, stop it.” I don’t actually think that’s that terrible. I was in this moment. What if someone actually did see that and they’re like, “This person thinks she’s a parenting expert. Her kid is licking the escalator at Heathrow. What kind of person is that?”

Zibby: I’m hoping he’s not fifteen years old.

Emily: He was three.

Zibby: Okay, good. That would be a different issue.

Emily: I agree. My kids are little. There is sometimes this feel that I am more cognizant than I might be about how people perceive my parenting choices, and sometimes at my kids’ school also. I don’t talk about the book at school. I don’t know how many people at this school know that I wrote this book. There always is this feel anytime you’re interacting with the parents of your kids’ friends. What does this person think about me? Particularly if you’ve then gone out and been like, “I wrote this book about how to be a good parent,” then when the kid comes home and they’re like, “This person’s kid pulls my shirt,” you wonder if the parents are like, “Oh, yeah. She thinks she’s so great at parenting. Her kid’s pulling my kid’s shirt.”

Zibby: In preschool especially, I see all these moms every day for two seconds. “Hey. How are you?” They should do some sort of two-minute video on each parent. Look at what a cool job you have. They might not even know. There should be a “Let’s get to know the other parents. Watch the little video.”

Emily: I totally agree. My daughter, she’s been in the same school since she was three. Now my son’s there too. Because she was our first, we actually got to know a lot of the parents. A bunch of the parents in her class, I know. Somehow, I haven’t invested in my son’s class in the same way. I don’t know anything about the parents. I feel a bit bad because as you say, I’m guessing many of them have very interesting jobs and would be interesting to talk to, but I don’t know.

Zibby: I have four kids. It took a while for me to gear up for my fourth kid’s class. What are his teachers’ names? Who are the parents? Now finally, he’s been two years in the same class, and now I know them. I was like, “I do not have the bandwidth for another set of parents.” Now, they’re great people. I’m so happy I know them. I needed the little video. Anyway, this is off topic.

Emily: Little refresher.

Zibby: Yeah, a little refresher. You wrote a piece in New York Magazine recently where you wrote about the things parents actually need. What don’t parents really need? What do you think is totally superfluous?

Emily: There’s a lot of stuff that you buy in the first three weeks that you don’t turn out to need. I recall every time we had some issue with my daughter, we would be like, “I’m going to buy something to fix that.” We had a lot of stuff. I had a couple of thoughts. One is bottle warmers. You don’t want to train them to drink it warm. You want them to be able to drink it at room temperature. Rookie mistake.

Zibby: I made that mistake. I did that. Bad.

Emily: You’ve got to be able to take it out the fridge. It’s fine, tastes the same. It’s okay. That was one thing we had that was definitely not useful. The other thing was baby shoes. We got all these shoes for babies. My kids didn’t walk until they were sixteen months old. What are they doing with those shoes? Particularly because I dressed my kids in onesies from Target, it wasn’t even part of an outfit. I had these functional shoes and a belt. Somebody gave me a belt once for my baby. He doesn’t need a belt. The whole industrial complex of fancy baby clothes is something that some people really like. I could never quite get into because they pooped on everything.

Zibby: There’s so much pressure before you have kids to get it all right and get everything you need. In this day and age, you can get something in an hour delivered to your door — I’m here in New York — not everybody. If I didn’t have the Aquaphor, I could get the Aquaphor later. I felt like everything had to be ready and stuff.

Emily: You should have Aquaphor.

Zibby: I have Aquaphor. I have Aquaphor in every cabinet in my house. We use it for everything.

Emily: Me too, the tubes, the tub, the little tubes.

Zibby: Me too, travel size.

Emily: Good for everything. That is the most useful product.

Zibby: I had some itchy something in the back of my head the other day. My nanny was there. She’s like, “Let me put a little Aquaphor on that.” I was like, “Okay.”

Emily: It works as a lip balm. One of my friends is pregnant. She was like, “Is there anything I’m missing?” I was like, “Look, you can order everything. One thing is you need to have some formula in the house. There could be a moment when the breastfeeding’s not working and your kid is really hungry and you want to give them a little bit of formula. It’s going to be three o’clock in the morning, for sure. If you don’t want your spouse to have to drive out, you’ve got to have a little bit of that around, little bottles.”

Zibby: That’s true, totally. I just wrote this article on What’s Up Moms where I pick more books for how to be a more relaxed parent. I include your book. At the end, I was like, “I need this for preteens,” because my older kids are almost twelve. I was like, “What do you think, Emily Oster?” Are you getting to that? I spent five minutes last night as I wrote questions to you thinking of funny names for teen books. Then I was like, “I cannot send these to her.” These are not funny and I’m really tired.

Emily: The problem with doing the next phase is that the data part of this becomes so much worse. I felt this even in this book as you get into some of the questions people will have more about older kids, like, “Can you teach my three-year-old to read?” and so on. Our data is very poor on that. What’s the right kind of preschool? Is a Montessori school right? Is a play-based preschool right? The answer is that depends on your kid. Number one, we have almost no data. It’s not even that easy to imagine how we would run that kind of study because the kinds of kids who are going to benefit from Montessori may be different than the kinds of kids who will benefit from something else. There’s too much heterogeneity, too many differences in the effects of those things on kids to really analyze them. The data in that part is very poor. Then you’re left with just structure. You write a book. There’s how should you think about the kind of decisions that will come up with preteens or even with six-year-olds? It’s a much more complicated space. I find parenting my eight-year-old to be really fun and in some ways much less exhausting, but also a lot more complicated than the little ones.

Zibby: Wait until eleven. I’m sure parents out there who have college, they’re like “You think it’s hard at eleven. Wait until fourteen.”

Emily: I have a story at the end of the book about these older colleagues. We had dinner at their house. Our kids were one and four. Their kids were fifteen and nineteen or something. I was like, “When our kids are older, we’re going to .” They’re like, “We thought that. Actually, when our kids were both in high school, we spent every night — we spent three hours talking about how to make them happy.”

Zibby: I had an author come in the other day who is a little older than me. I was like, “I’m so sorry. I haven’t slept all night. Both my kids woke me up. It was one of those nights. The dog was barking.” She’s like, “Me too because my two older kids had friends over until two in the morning. The music was blasting.” Oh, my god. It’s never going to end. I’m doomed. Do you think you’re going to write another book?

Emily: I don’t know. If I wrote another one, it would probably not be about this. Maybe it would be about diets. This is more like what I’m working on. A lot of these same issues come up, the same limits to the data and how do you think about biases that come up a lot in that? That’s actually much closer to my academic work. I don’t know. I’m not sure. I took a long time to decide to write the second one because I wanted to be sure that I knew what I was going to say. I don’t know what I’m going to say in a third one. We’ll have to see. Stay tuned. Wait seven years.

Zibby: No pressure. I’ll wait seven years. My kids will be out of my house by then. No, I’m kidding. Do you have any advice to aspiring authors?

Emily: A lot of academics ask me about writing books. Regular people who want to write books don’t ask me. Academics ask me. The main thing I tell them is if you’re going to write a nonfiction book, it’s best to know what all the chapters are first. A lot of people start with, “I have one really good point that I think other people should know about.” That’s a great reason to write an article. Where the writing of books becomes onerous and unpleasant is when you have to write all the chapters. You want to make sure that you are planning to write all the chapters before you commit to writing any of them.

Zibby: Excellent. I know you’re not going to write a book about teens. Now I feel like I’m going to email you when I have to make major life decisions. What’s the data on this?

Emily: I’ll be like, “I don’t know. Do whatever.”

Zibby: I’m not going to listen to you anyway. I’m just going to do my own thing.

Emily: Exactly. That’s the whole thing.

Zibby: Thanks so much for coming on “Moms Don’t Have Time to Read Books.”

Emily: Thank you for having me.

Zibby: Take care. Bye, Emily.

Emily: Bye.