Emily Oster has made a career out of trying to debunk conventional wisdom.
She’s tackled popular beliefs about HIV, pushed back on Nobel-Prize winning economist Amartya Sen’s research on missing women in the developing world, and in her first book, questioned the advice that pregnant women abstain from alcohol. “Emily Oster may have the highest controversies-generated-to-years-in-academia ratio of anyone in her field,” Esquire magazine once proclaimed.
Now a professor of economics at Brown University, Oster has maintained this drive to disprove conventions with high-quality data. And she’s following up her 2014 book about pregnancy, Expecting Better, with one on parenting called Cribsheet: A Data-Driven Guide to Better, More Relaxed Parenting, from Birth to Preschool.
Quartz spoke with Oster about the millions of decisions parents are expected to make about their babies’ health, sleep, screen time, schooling and more. Her goal, she explains, is to give parents the framework they need to make informed decisions about raising their kids.
This interview has been lightly condensed and edited for clarity.
Quartz: You are an economist. How has your background helped you write a pregnancy and parenting guide?
Oster: Economics brings two things to the table. The first is a structured system for how to think about decisions, and the second is a somewhat obsessive focus on causality in data. Both of those come together in the kinds of questions people are asking in pregnancy and parenting. I think the first step there is always to think, “What are the costs? What are the benefits of those different choices?” And then you need to have some data in order to make those choices.
But when you go to look for those, you realize that a lot of the literature on these questions is not very good, and that even when people say, “There’s a relationship between this behavior and this outcome”—often those relationships are not causal. I think that my training in seeing what’s a causal link and what’s not a causal link is a really important part of these books.
Many parents don’t have the knowledge, time, or tools to sort through the data out there. What are some of the basic concepts you think they need to know in order to look into these questions?
There’s broadly two kinds of evidence that we see in these kinds of questions. One is evidence from what we call a randomized trial, where people are trying to evaluate some choice, and they randomly choose some people to do one thing and some people to do another thing, and then they compare them. And that evidence tends to be pretty good, because it sort of shucks off all the other differences across people.
It turns out that a lot of the data that we actually have in things like parenting and pregnancy, but even more so in parenting, is from what researchers would call observational data: Basically, evidence that comes from comparing people who do one thing to people who do another thing. And the problem with that is that the choices that people make when they parent are not made randomly. People think a lot about their choices, and their choices are influenced by the constraints that they face, and other things about their families. And so it’s very hard to learn about the impact of something like breastfeeding by comparing people who breastfeed to people who don’t, because there are all kinds of differences across those families.
Your book covers a lot of ground, but it can’t cover every possible question that will arise in the course of pregnancy and after birth. For those other questions, how can parents access reliable answers?
Not just the Internet. Not Facebook.
I think that one place people can and should look is in the medical literature. If you really want to know the answer to something and know the best evidence [for it], sometimes the only thing to do is to go to the primary source. That stuff is surprisingly available online, I think the bigger problem is that it’s not always so easy to figure out which studies are good, and it can also be difficult sometimes to just read the studies.
And we also sometimes have to confront the fact that, in many cases, there just isn’t especially good data…and sometimes you’re going to have to make these even very important parenting choices without having all the information. Confronting that is also a pretty important part of trying to make the right choices.
Social media is a very popular place for parents to turn to for answers and community. But it’s also a place where misinformation or “parenting myths” can prosper. How does your data-driven approach help?
I joked about Facebook, but I actually think there’s something very nice about the social media landscape, which is that it does provide a community which can be so valuable, particularly at the beginning of parenting, when you’re just so overwhelmed and you’re looking for people who are going through the same thing as you, and it’s 3 o’clock in the morning, and it’s pretty great to have other people you can talk to.
Where we get into trouble…is that it’s important to have information. In some sense, the data about many of these questions are going to be the same for everybody, but the actual choices that you’re going to make as a parent should be influenced by what is going to work for your family. And much of the discussion in this parenting book in particular is around trying to help people think about what is going to work for their family. I think there’s a little bit of an issue sometimes when people try to give other people advice or try to get advice from other people and they say, “You should just do the thing that I do.” Well, actually, that may not be the right thing for your family.
The example I give in the book is about circumcision. There are some data on circumcision, but ultimately, I think for many people, the decision about whether you should circumcise your kid or not is going to come down to evidence and the cultural tradition in your family. Those things are not pieces of information that you can garner from other people. The lady on the Internet doesn’t live in your house and she doesn’t know what’s best for your kid’s penis.
There are a lot of other things about parenting that are similarly personal and controversial, like breastfeeding, for example.
People make claims about the benefits of breastfeeding that are extremely broad; not only is it good for early life health for your baby, but it’s the way to give them the best start, it’s important for IQ, for weight later, for many long-term outcomes. But the kind of women who breastfeed are very different from the kind of women who don’t. They tend to be better-educated, richer, white (in the US), married, and older, and many of those things are also linked with better outcomes for kids. So it is very hard to separate the effects of breastfeeding from those things.
When you look at [more neutral] evidence, you do find some benefits of breastfeeding. There is evidence that it is helpful for digestion early in life, that it lowers incidence of diarrhea in the first year of life, but there are many of these claims that people make that simply aren’t supported in the data. For example, the claim that breastfeeding lowers respiratory infections in the first year doesn’t have support in the data. Claims that breastfeeding lowers obesity rates when your kids are older? Not supported in the data. Claims that breastfeeding increases IQ? I argue it’s not supported in the data. If anything, the main long-term outcome that does seem to have some support is a lower risk of breast cancer for the mom, having nothing to do with the kid.
Breastfeeding is hard, and particularly for women who struggle or who can’t do it for some reason, there is this real sense of failure. And trying to be a little more objective about what are the actual benefits hopefully will make some people feel better.
What are parents supposed to do when they get conflicting advice from different, reliable sources?
Unfortunately, the world is full of somewhat contradictory messages on some of these things. Giving people that window into both, what does the best evidence say, and then also, what does some of the other evidence say, and then why is some evidence better than other, that’s part of what I’m trying to do here.
What’s your book’s biggest takeaway for parents?
It is important to be confident in the choices that you make. With both books, I am trying to give people a framework to understand the decisions that they are making and make what they view as informed decisions for themselves—decisions that they can be happy with.
Read more from our series on Rewiring Childhood. This reporting is part of a series supported by a grant from the Bernard van Leer Foundation. The author’s views are not necessarily those of the Bernard van Leer Foundation.