When Brown University economist Emily Oster became pregnant with her first child in 2010, she found herself drowning in a sea of conflicting advice. Should she give up coffee entirely? Should she eat sushi? Was a glass of wine ok? Was a prenatal test too risky to consider? In a world of heated parenting forums and “just trust me” rules, Oster decided that the world of pregnancy and parenthood needed a more data driven approach. And so she has transformed a personal quest for better guidance into a public mission, becoming a best-selling author and influential voice who insists that better information — paired with personal values — leads to better decisions.
Early Lessons in Economics
Oster’s faith in data-driven decision-making can be traced to her childhood. She is the daughter of not one but two economists: her late mother, Sharon Oster, was a trailblazing Yale School of Management dean, and her father, Ray Fair, is a longtime Yale economics professor. Dinner-table debates in the Oster-Fair household often came with an economic twist. Her mother taught her early about economics and the trade-offs that define every decision. “At the time, I didn't think that was weird,” she laughs. “Later, I became an adult and realized that was an extremely weird thing to say.”
But these lessons stuck. Growing up in New Haven, Emily watched her parents apply cost-benefit logic to everyday problems. In one oft-retold example, Sharon Oster persuaded a local grocery store to install a fax machine so she could order groceries remotely, explaining that her “high opportunity cost of time” made routine shopping trips inefficient(She should be memorialized as the unofficial founder of Instacart!)
Those early experiences imbued Oster with a deep belief: good decisions start with good data. And so she’s devoted her considerable talents as an economist to helping people approach everyday decisions in a data driven way. But Oster’s methodical approach to life isn’t just about cold rationality. She emphasizes that while data informs decisions, personal values and emotions ultimately shape them. “Two people can see the same data and make different choices because their preferences are different,” she explains. “You could call that preferences, you could call it emotion, but at the end of the day, it's how I feel about something and how much I care about it being important in my decision-making.”
This mission to apply data to everyday decisions came from a very personal place: her own first pregnancy. It was until then that she realized just how poor some of the evidence base was in the medical world. “Pregnancy seemed like a world of arbitrary rules,” she says. One that particularly irked her was the 35-year-old cutoff for amniocentesis. “I was 31, and I wanted more certainty,” she recalls. “But they treated me like a nutter—like only a crazy person would ask for this test at 31 because everybody knows that 35 is the magic number.” But as an economist and a rationale human being, Oster knew biology didn’t work in sharp cutoffs. And furthermore, the information that could be gleaned from that test was important to her at the time. This experience planted the seed for Expecting Better, where she examined pregnancy advice through the lens of data.
Expecting Better
Like many first-time moms-to-be, she felt overwhelmed by rules (no sushi, no coffee, no wine) and horror stories lurking in every Google search. So, drawing on her economics training, she began scrutinizing the actual scientific research behind common pregnancy directives. The result was her 2013 book Expecting Better, a kind of fact-finding examination of common pregnancy advice. For example, she found that moderate caffeine intake during pregnancy wasn’t the baby-endangering sin it was made out to be, and that the risks of certain prenatal tests had been overstated. By translating reams of medical studies into plain English, she gave women permission to worry less and make informed choices about everything from deli meats to epidurals.
The approach struck a chord. Expecting Better became a best-seller — it has sold around a million copies and been translated into 19 languages and turned Oster into an unlikely parenting guru. Readers were relieved to finally see numbers instead of scare tactics. Amid an often judgmental parenting culture, Oster’s tone was refreshingly non-preachy. She presented the facts and figures, then effectively told parents: It’s your call but understand the data. As comedian Amy Schumer affectionately put it, Oster became “the non-judgmental girlfriend holding our hand and guiding us through pregnancy and motherhood.”
When I asked her to reflect on where she would like to see the pregnancy community focus, she quickly offered work aimed at providing moms the birth experience they desire while also ensuring quality, safe outcomes.
“I would love to see a greater use of midwives relative to obstetricians, not because I don't love obstetricians, but because I think their time is more valuable and that for many patients, a midwifery approach is amazing, particularly for lower risk patients. A midwifery approach is a really good one…midwives can give more time to get questions answered and can facilitate a different kind of birth experience.”
Here, Emily also offered some caution. She mentioned that there’s some advice out there encouraging women to delay going to the hospital as long as possible. People hear that “you’re going to be a cog in the wheel..that the hospital is a terrible disaster of interventions.” This is why she said its so important to create birth experiences for women where they feel listened to and safe. Zooming out, Emily's advice resonates broadly with today's crisis of trust in healthcare: at a moment when public confidence in institutions and experts has sharply declined, genuinely listening to people's concerns is crucial to restoring that trust.
Cribsheet
In her follow-up book, Cribsheet (2019), Emily tackled the next phase — the tumultuous years from infancy to preschool — with the same data-driven lens. From breastfeeding and sleep training to screen time and potty training, Cribsheet parses what the best available research says and what it doesn’t. Oster’s aim, once again, was to cut through myths and guilt-inducing folklore. Is breastfeeding really “essential” for a child’s future IQ? Does co-sleeping doom your baby’s independence? Instead of handing down edicts, Oster lays out the evidence on each side so parents can make choices aligned with their own comfort and needs. It’s an economist’s version of a parenting manual: less NY Times Op-ed, more Wirecutter. And if the data shows that multiple approaches are fine, she’s the first to say: do what works for you.
One example she wrote about in her book was about conventional breastfeeding advice. She’s the first to say that breastfeeding offers some short-term benefits like “reduction in gastrointestinal illness, some reductions in allergy and asthma, some impacts on ear infection. However, on some other purported benefits, she has her doubts.
“All the claims that are made about long-term health, about IQ, are just not well supported in the data and the messaging.” She also opened up about some of the more bizarre claims circulating around like “breastfeeding will improve your friendships…it’s going to make your kid taller or thinner or have better hair or have less neurodevelopmental problems…put it in the bath…it heals wounds!”
For the record: it doesn’t do any of those things.
She takes issue with the “Breast is best” messaging not because its necessarily wrong but because of the message it sends to women who can’t breastfeed for whatever reason. People hear that “if you don't do this, your kid will be a loser…and that is not true!”
Another example is sleep training. As a parent of 3 sleepless children that each find 4 am an hour of spiritual rebirth, I was particularly curious. “A lot of people worry that sleep training is going to ruin their child's attachment to them… That's the claim that's out in the world. And the origin of that is evidence from Armenian orphanages in which kids were not only left to cry it out, but also just left alone for days and days without any human contact. And also there was a tremendous amount of abuse… really not very comparable to the kind of circumstances that people are talking about now. If you look at randomized studies of sleep training, it tends to improve sleep for kids and for their parents, tends to improve mood, marital satisfaction…they're happier. And when you look short and longer term, you don't see any differences in attachment…So I think these kind of claims that sleep training ruins your kid, I don't believe those to be supported by data... It's also not a magical solution that will fix every sleep problem forever…I think it's important to give people like a realistic sense of the success here, which is that it improves sleep typically for many kids.”
This empirical approach to parenting has earned Oster a devoted following of moms and dads but It has also, at times, put her at odds with parts of the medical establishment. Some experts bristle at an economist wading into their territory, especially when her interpretations challenged long-standing recommendations. I personally find this sort of criticism silly. If you have better data, show it! Oster, for her part, has never claimed to have all the answers. But she has made it her brand to ask: What does the evidence actually tell us? And if the evidence says one size doesn’t fit all, she’ll gladly break from orthodoxy to point that out.
The Social Media Dilemma: Finding Nuance in the Noise
As her own children grow older (they’re now school-age), Oster has turned her analytical eye toward the next big frontier of parental angst: screens and social media. From TikTok trends to endless video game battles, many parents worry that modern digital life is poisoning their kids’ minds. In fact, David Brooks recent screed against the stupidity of tariffs invoked screens as a root cause of national cognitive decline. True to form, Oster is approaching these fears with data and level-headed skepticism. She acknowledges that the headlines can be scary – teen depression, bullying, body-image issues – all highlighted by Jonathan Haidt’s recent book The Anxious Generation and Vivek Murthy’s recommendation that social media be stamped with a warning label.
Emily started our conversation by emphatically stating one thing: “I feel very strongly that we should not have phones during the school day. I don't think that we need to have notifications pinging you all the time while you're trying to learn at school. So I think that is actually pretty clear and I think there's pretty widespread agreement about that.”
But she urges parents not to succumb to techno-panic without examining the evidence. And she believes that the available research suggests a more nuanced view.
“There are some kids who clearly benefit from social media in some ways and some kids who are really clearly very, very harmed.” And here, Emily lands on the timeless but tricky question: What will work for my kid?
This is an area I’ve been thinking about a lot lately - namely, does screen time irreversibly change our brain in ways that permanently affect attention and/or emotional regulation? For example, a study in JAMA looked at fMRI data[a type of MRI where we analyze blood flow patterns in the brain] and found that adolescents who frequently used social media had altered sensitivity to social rewards and punishments, particularly in areas of the brain called the amygdala and prefrontal cortex. While these are ultimately correlations, these findings nonetheless cause understandable concern.
From a first principles perspective though, what are social media apps designed to do? Quite simply, they are built to steal your attention with their constant notifications and personalized content. And as parents, that’s something it seems we have complete agency to control. For example, moderate screen time in a supportive environment might do no harm, or even some good (think connecting with friends or creative learning), whereas endless unsupervised scrolling into the night clearly isn’t healthy. And therein lies the challenge - as Emily says, “The hard part about navigating this as a parent, ultimately is training your kid to moderate their screen use.”
To get some further guidance, I went to the website of the Child Mind Institute which has a wealth of great resources. There, they had some guidelines to help parents figure out if their child is ready for social media. For example, children with poor impulse control, inability to read social cues, or hypersensitivity to criticism, they argue, may not be ready for social media. When reading this, I thought of many adults that fit this criteria but that's for another day! Here, Emily offered that these were perfectly sensible recommendations but ultimately, for me, they raise further questions. How much impulse control should my 12 year old have? How do you define age appropriate sensitivity to criticism? To the extent these are user friendly heuristics, I found them wanting.
When I asked her what study she would love to do to help move this discussion forward, she was very practical. She said parents often tell her “well, I have to give my kid a phone because everyone else has a phone… And then they'll be left out.” So the study she wants to run would randomize kids into groups that have varying access to phones. For example, if 70% of kids don’t have a phone, do the other 30% that do ignore their phones as a result? “Where is the tipping point at which actually working together as a group actually helps?”
Her scientific approach brought me back to Emily’s broader ethos: avoid knee-jerk extremes, look at credible data, and then make a balanced plan that reflects your unique understanding of your family and your children (You can see more of her thoughts on this topic on her website Parent Data) Ultimately though, phones and social media are not going anywhere…so we will have to figure out how to manage them in our children’s lives.
Pandemic Pivot: Weighing the Risks of Reopening Schools
In 2020, Oster’s reputation for clear-eyed analysis led her straight into one of the most explosive debates of the COVID-19 pandemic: school closures. As the mother of two young children, she was deeply concerned with how the virus – and our response to it – would affect kids. She put her skills to work collecting data on COVID cases in schools across the country. By the fall of 2020, Oster had partnered with data scientists and school administrators to gather real-time statistics from thousands of schools, ultimately covering 47 states. The numbers that came back surprised many: over the last two weeks of September 2020, roughly 200,000 students attending in-person school had an average COVID-19 infection rate of just 0.13% (about 1 in 800 students), and staff had a rate of 0.24%. Even in higher-risk communities, the school infection rates were well under half a percent. In early October, Oster publicly reported these findings and made a bold assertion: schools were not the feared COVID “super-spreaders.”
What’s more - while there was a lot of reasonable concern about infection and its impacts from in-person learning, there was also actual evidence of academic harm. “It was pretty clear to me and all other parents on planet Earth that Zoom school was not really school. It wasn't as good as regular school. But it was hard to know exactly how much worse it was.” So Emily looked at the data from a commonly used online math platform called Zearn, which showed
“Everyone’s math learning had totally tanked…it was particularly bad for kids in poor school districts…Think of the kids with fewer resources when they were faced with this Zoom school option with no computer and two siblings at home they're supposed to take care of because their mom needs to work at the grocery store… putting all that together, it was just crystal clear that school is really important. Kids need school. They need school for learning. They also need school because school is providing a lot of services. And so I came into that first summer of 2020 with the idea that figuring how to reopen this should be our number one priority.”
Coming at a time of immense anxiety, this message was both welcome and controversial. Many parents and pediatricians took heart from Oster’s data, seeing it as a beacon of hope that kids could return to classrooms with reasonable safety. But to others — notably some teachers’ unions and cautious public health officials — her push to reopen schools sounded reckless. Emotions were high on all sides. When I pointed out that there was a mortality and morbidity to decisions like these, Emily naturally countered with a data driven view. When evaluating these options, “let's understand how big those effects are. And that was something that we were missing[at the time].” The question people posed then was “ well, what if somebody gets COVID? Yes, somebody will get COVID at school… Just like every year, people get flu at school. Every year, people get a hand, foot, and mouth at school. Every year, people get the norovirus at school. Some of them get very sick.” But we are willing to make those tradeoffs because of the benefit of school. Moreover, there is morbidity and mortality to missing school as well, which she felt people were ignoring.
“By keeping kids out of school, more of them die, and they die early. And that’s because we know that some of those kids will never go back to school and they'll end up with less education in the long term, and that is a contributor to mortality.”
In her view, the arguments being made were hopelessly one sided and not guided by the data. And as a parent and a scholar, she just felt obligated to point out a data driven approach to the problem of school reopening.
Still, that nuanced stance got lost in the political furor. Oster soon found herself at the center of a national debate she never anticipated. Critics questioned why an economist was steering such discussions. Some opponents lobbed vicious attacks; at one point, angry detractors on social media derided her as a heartless “teacher killer” for advocating reopening. The blowback became intensely personal, a shock for a scholar more accustomed to academic disputes than public vilification.
Yet as heated as things became, Oster largely stuck to her empirical guns. When I asked her how it felt to be at the center of some very public criticism, she responded “I have a thin skin but a short memory... It is important to me to try to say things that I think are true…if people criticize you, it doesn't feel nice but ultimately It's not that important…it’s just part of the job.” Said differently, if you want to be a truth teller, you have to be comfortable with being misunderstood or vilified. Indeed, she weathered the storm and was later vindicated to a degree: subsequent data from the Centers for Disease Control and other researchers eventually backed many of Oster’s early findings on school safety. Looking back, she has no regrets about standing her ground. If anything, the experience reinforced her belief that data must guide tough decisions — especially in a crisis.
On Building Trust in the Public Sphere
I asked Emily what lessons she’s learned since being in the pubic eye. She recounted an article she wrote in 2021 in the Atlantic around the relative risks of COVID infections in kids vs elderly adults which she labored to write with nuance and an eye towards helping parents make data driven decisions for their children. However, the headline itself “ Your unvaccinated kid is like a vaccinated grandma" was derided as insensitive. “I learned a little bit more about how to communicate when I think my point is more subtle…I think when you are talking about things like this that people care about and where they disagree, it is very important to think exactly about the words you pick and to not have people feel that you are being dismissive…And that was an important lesson.”
A recurring question on Good Medicine has centered around how truthtellers can have more impact in our world. Like Sanjay Gupta, Emily recommends honesty and authenticity. “Tell people how certain you are… Why do I know this and how sure am I and what further information could I get that would change what I'm thinking?” She also said something that made me reflect:
“People have to be seeking you….Its very difficult to be compelling if people aren’t ready to hear and trust you.”
This strikes me as true whether you’re in the public eye or sitting directly in front of a patient. People have to want to hear from you if you have any chance of persuading them.
Emily work underscores a truth that deeply resonates with us at Roon: data can inform, but it can’t dictate. Like Emily, we believe in the power of evidence-based decision-making — but we’ve also learned that trusted data alone isn’t enough. People need to feel heard and supported, not lectured and scrutinized. We believe strongly in this approach because the best decisions come not just from knowing the data, but from understanding the person behind them.
Beyond Persuasion
To me, an important legacy of Emily’s work is not that she’s trying to convince people of anything in particular. Rather, she’s trying to teach everyone how to use data to inform life’s everyday choices. Yes, it's of course important that people at least listen to evidence-backed institutions and doctors (that have earned that trust), but it’s also equally important that everyone have the data and toolbox to inform the decisions they’re making. Said differently, Oster is just an economist who cares deeply about helping people use data to make better choices for themselves. I think that’s something we can all get behind.
Quick Hits
Recent book rec?
"The Waiting Game - about the ladies-in-waiting of Henry VIII’s wives"
Favorite podcasts?
"CITIUS MAG and Ali on the Run - I just like podcasts where people talk about running with runners. It's really niche."
Mentor who shaped you?
“Steve Levitt of Freakonomics. He’s been really thoughtful, especially about public-facing economics.”
Dinner guest, living or dead?
“Richard Feynman. He seemed like a great teacher of really hard things.”
Dr. Rohan Ramakrishna is a Professor of Neurosurgery at Weill Cornell Medicine and one of the founders of Roon.
