Over the course of a few days in mid-May in Providence, in between homeschooling her 5- and 9-year-olds, grading undergrad research papers, baking bread, revising her first book, and co-chairing Brown University’s Healthy Fall 2020 Task Force over Zoom, Emily Oster sat down in front of her laptop with a steady supply of coffee. A few months earlier she’d started writing a newsletter called ParentData, aimed at the following of pregnant women and new parents she’s amassed over the years. It started as a guide to making data-driven decisions about such things as side sleeping and sippy cups. But as with everything else, the pandemic had taken over. She’d wake up each day to an inbox full of frantic questions: Was it safe to visit the grandparents? Are play dates off the table? What about sending kids back to school?
Oster, an economics professor, has built a thriving career applying the tools of her discipline to everyday life. Her first book, 2013’s Expecting Better: Why the Conventional Pregnancy Wisdom Is Wrong—and What You Really Need to Know, shot her from academic obscurity to household name. It dug into data to bat down blanket bans issued by obstetricians (including hers during her pregnancies) on deli meats, sushi, and alcohol. “Economists’ core decision-making principles are applicable everywhere,” she wrote. “And that includes the womb.”
Now Oster is using those principles to help people think about two of the most vexing issues of the Covid-19 era: how to stay safe, and how and when to reopen day care and schools so America’s 74 million children, their parents, and the economy can reclaim some semblance of normalcy and productivity. Although her analyses on school reopenings have been criticized as too cavalier (and aligned her more closely with President Trump than she’d like), she’s become a go-to authority amid the anxiety, with bylines in the Atlantic, the New York Times, the Washington Post, and Bloomberg Opinion, and appearances on an array of podcasts.
As for those questions piling up in her inbox in May, Oster couldn’t possibly respond to or decide what was best for each newsletter reader’s unique situation. But she could share the economic framework she uses when faced with uncertainty. So she got to typing:
- Frame the question. (Clearly define two or three options, instead of trying to evaluate infinite or indistinct possibilities.)
- Mitigate risk. (What’s the safest way to execute those options?)
- Evaluate risk.
- Evaluate benefits. (Don’t overlook these.)
The point of the exercise, Oster says, isn’t to feel sure, necessarily, that the decision you reach is the right one. That may be possible sometimes, but it’s very difficult now, as research into the virus yields new and changing information and much of the data we’d like to have is unavailable or incomplete. The goal is to feel good about the process you used to arrive at a decision, so you can move on to the next fire you need to put out.
The message wouldn’t have felt unfamiliar to anyone who’s taken Econ 101 or replicated Benjamin Franklin’s habit of stacking pros against cons. But it struck a chord, and the post soon became Oster’s most popular, with more than a half-million views. As she often does, Oster shared the decisions she and her husband had made regarding the topic at hand—“Even though I know I will be crucified, I will tell you,” she wrote. They paid a young nanny who lives alone to watch their kids in the afternoons when schools closed in March so they could continue working, and arranged visits with the grandparents via socially distanced, masked walks in the woods.
Oster is 40 and has bright eyes, a wide smile, and straight chocolate-brown hair that she wore for years in a bob but now pulls back into a “Covid ponytail” after tiring of looking at herself on Zoom calls all day. In addition to Expecting Better, she’s the author of 2019’s Cribsheet: A Data-Driven Guide to Better, More Relaxed Parenting, From Birth to Preschool, an instant Times bestseller. The books have made her a celebrity among a generation of women and new parents like me, arming us with the ability to make informed, confident decisions. Her writing is accessible, authoritative, and empathic, infused with a self-deprecating wit. “Last week is when I started to crack a bit,” she wrote in ParentData on April 27. “Was that me crying in the Whole Foods parking lot last Thursday? Yes, yes it was.”
Oster made her classroom debut as an infant in 1980, when her father, Ray Fair, held her up Lion King-style in a Yale lecture hall. “I figured that since we’ve been talking about production functions all semester, you’d like to see the output,” he told his students, as one of them recalled in the school’s alumni magazine. Fair, a macroeconomist known for his presidential predictions (he foresaw a Trump victory in 2016; he hasn’t made a 2020 call because the pandemic has messed up the economy and hence his model), still teaches there. Oster’s mother, Sharon Oster, was also a Yale economist until retiring in 2018. She was the first woman to gain tenure at and become dean of the university’s School of Management.
The Oster-Fairs brought economics instruction home. Food shopping was a lesson in opportunity cost: Time was valuable, so Sharon faxed the grocer a list instead of walking the aisles. Fair would dismiss his children’s pleas to switch to a shorter toll booth lane by citing the “no arbitrage condition,” which assumes that because everyone is optimizing all the time, the possibility to improve is marginal. Feminism was demonstrated, not simply discussed. The couple alternated nights fixing dinner, despite Sharon’s being a better cook, to show it wasn’t solely a woman’s job. Sharon didn’t change her last name upon marrying, and she and her husband flipped a coin to decide whose Emily would take, Sharon told me, “to let children reflect upon the nature of patriarchal culture and society.” (For Emily’s two younger brothers, they alternated last names.) Emily was a bright, driven, and bossy child, the sort who created an algorithm to solve quadratic formula problems for sixth grade math. The teacher made her redo the work by hand.
After graduating from boarding school, Oster entered Harvard, thinking she’d major in biochemistry. That changed after a summer working two jobs: one in a biology lab dissecting fruit flies and the other assisting Christopher Avery, an economist at Harvard’s Kennedy School, on a book about college admissions. The purview of economics felt broader. “I liked the idea of being able to answer big-picture questions about what’s going on in the world,” she says. Avery would prove instrumental in her personal life, too—he introduced Oster to her now-husband, Jesse Shapiro, also a Brown economist.
As she began her doctorate at Harvard in 2003, Oster turned to the intersection of economics and health. She saw an opportunity to shed new light on the HIV/AIDS epidemic ravaging Africa. Oster argued that the prevalence of other sexually transmitted diseases there played a larger role in HIV transmission than researchers previously thought and that treatment wasn’t cost-effective. (The World Health Organization pushed back: “Narrow cost-effectiveness arguments sow confusion and legitimize further delays in providing care to the millions now living with HIV.”) She used mortality data to posit that the United Nations was overestimating HIV infection rates by as much as three times. By age 27, she’d delivered a TED talk on the topic, consulted for the President’s Commission on AIDS, and been named the “future of economics,” alongside Shapiro and a few others, by the Times.
It was also during these years that Oster had one of her biggest fumbles. Part of her dissertation challenged Nobel Prize-winning economist Amartya Sen’s idea that Asia suffered from a 100 million “missing women” problem as a result of gender discrimination and misogyny. Oster posited that almost half the problem could be explained by pregnant women having hepatitis B, which correlated to birthing boys. The Journal of Political Economy, co-edited at the time by University of Chicago economist Steven Levitt, published it in 2005. Levitt and co-author Stephen Dubner lauded it in Slate just as they were rocketing to fame with the release of Freakonomics, a blockbuster that’s been praised for bringing economics to the masses and panned for debasing the discipline with cleverness. The paper raised eyebrows throughout the field: Who did this young woman think she was?
In this case, the critics were right. The following year researchers in Taiwan contradicted her findings using a larger data sample. She ended up traveling throughout China to collect better data and correcting herself in a follow-up paper. When the Wall Street Journal wrote a feature on the about-face, she said it was the responsible thing to do. “This is the way science works,” she said.
Oster left Cambridge in 2006 to do a postdoc and teach at the University of Chicago, where Shapiro had begun his postdoc the year prior. The two married that year, bonded by a shared love of efficiency and structure. They hash out big decisions mostly over email and track family to-dos using project-management software. Upon learning she was pregnant with their second child, Oster alerted Shapiro via a Google Calendar invite to the due date. She became a regular contributor to Slate and wrote a short-lived advice column for the Journal, explaining how to apply concepts such as diminishing marginal utility and comparative vs. absolute advantage to child care and marital chore-splitting.
The idea for Oster’s first book was born in 2010 during her first pregnancy, with daughter Penelope, when her obstetrician’s dictates about what to eat and how to sleep felt patronizing and didn’t come with data. She scoured the research to weigh risks and benefits for herself and distilled it into Expecting Better, triggering the ire of doctors everywhere. The book has become a wild success: It sells more copies each year than the last. Yet Oster’s decision to write a book for the masses—analyzing and synthesizing other people’s research, instead of originating her own—isn’t necessarily currency in the world of academia. In 2014 the University of Chicago invited her to apply early for tenure, then rejected her. “It was the worst,” she says, “like, really, really terrible,” and threw into question her worth and identity.
Oster and Shapiro soon landed at Brown. Its economics department didn’t have the cachet of Chicago’s but brought with it the benefits of tenure for both and proximity to their families. She’s since given birth to their son, Finn, been promoted to chair of Brown’s tenure and promotions committee, and been named the Royce Family Professor of Teaching Excellence.
In 2019 she published Cribsheet, whichexplores what evidence says about sleep training, language development, and vaccinations. It made waves for its stance on breastfeeding: If you do it, great, but if not, don’t feel bad, because the benefits are overblown. Her critics were now speaking more loudly. Lori Feldman-Winter, chair of the American Academy of Pediatrics Section on Breastfeeding, faulted Oster in the pages of the New Yorker for not being an epidemiologist, accused her of misinterpreting research, and compared her to anti-vaxxers.
Over many hours of Zoom interviews with Oster, it became clear to me that though criticism doesn’t shake her confidence, her failure to publish a significant amount of original research, the standard metric by which her field measures success, does. (It probably doesn’t help that Shapiro is considered one of the country’s top economists as measured by said metric.) But people everywhere look to her for answers, I said one day as she fixed her kids lunch. What’s that feel like? “It is cool, kind of weird, and a little scary,” she replied. “Somebody said to me recently, ‘You’re the only person I listen to.’ And I was, like, ‘Oh, my God.’ ”
By early April, Oster’s followers knew the pandemic had led her to update her family’s emergency food kit with a 5-pound jar of peanut butter, alternate between “frantic obsession with the mundane” and “existential dread,” and begin cutting her kids’ hair. (“It’s bad. Really bad.”) The number of young people out of school worldwide peaked around this time at 1.6 billion, or more than 91% of the global student population, according to Unesco. About half have since returned to class. But particularly in the U.S., which has failed to contain the virus, the questions of when and how to reopen schools continue to trouble and polarize.
With no national reopening plan, the situation varies vastly depending on geography. The hedge fund Brevan Howard set out in August to compile data on the 100 largest U.S. school districts and found that 75 had opted for virtual instruction, 16 for in-person, and 9 for a hybrid. The economic implications are staggering. Brevan Howard estimated that 4.3 million working parents (read: mostly women) will be forced to reduce work hours or quit their jobs altogether, an outcome that “may be as disruptive to the labor market as a small-to-medium-sized recession,” it says. “Investors need to add schools to their usual dashboard of economic indicators.”
Oster has broadly argued for reopening schools in person. The circumstances under which she says that can happen safely are far more nuanced than those backed by the Trump administration, which has pushed for an open-no-matter-what approach. But for parents desperate for their kids to return to class, the important thing is that she’s a yes.
When it comes to reopening society broadly, the WHO draws a line at 5% of Covid tests yielding positive results. Oster defers to this threshold: Places with infection rates higher than that shouldn’t reopen schools—or bars or gyms or water parks. Places with infections below that rate can reopen schools if they implement proven safety protocols, such as mask wearing, social distancing, and adequate ventilation. The ability to test and contact trace should be robust and timely.
Such measures require money. Oster argues they’re worthy, cost-efficient investments, because reopening schools brings critical benefits to the economy and society: Parents can work. At-risk kids will have a safe place to go and get fed. The learning losses documented when schools went online in the spring, hitting low-income and students of color the hardest, can be addressed. Oster has also used her platform to highlight the unequal reality of the U.S. education system. “Without more resources, there are many places where it simply will not be safe to open,” Oster said in a Brown webinar in August.
Oster’s views land her somewhere in the mainstream middle—closer to the National Institutes of Health’s Anthony Fauci than to people taking a hard line against reopening until the virus is effectively eliminated. The American Academy of Pediatrics also favors resuming in-person learning, where safely possible, noting the risks of not doing so include social isolation and missed signs of physical abuse and depression.
As vast swaths of the U.S. experienced summer infection spikes and Washington refused to provide schools with extra funding, many teachers and their unions lobbied districts to adopt distance learning. Brad Marianno, an assistant professor at the University of Nevada at Las Vegas, who’s been tracking union negotiations, says Oster’s work enables parents, antsy to get their kids back into the classroom, to press their case using data and not only feelings. “When you can begin to bring evidence to the conversation, that allows you to also have influence,” he says.
One issue Oster has held up to argue in favor of reopenings is child transmission. Data collected early in the pandemic indicated kids weren’t efficient vectors of the virus. But recent studies increasingly suggest otherwise, says Zoë Hyde, senior research officer at the University of Western Australia. She urges more caution as a result, saying schools shouldn’t reopen until an area’s case counts fall below what contact tracing can rapidly handle. “It’s true that school closures are associated with harm,” she told me. “However, I would argue that such harm is far outweighed by the harm of an unmitigated epidemic.” Oster remains unswayed. She continues to argue that younger children could safely return to school earlier than older kids, even in communities where test positivity rates exceed the 5% WHO threshold, as long as safety protocols are in place. Evidence shows that children rarely fall severely ill and are often asymptomatic. They also benefit most from face-to-face instruction.
Some people are taken aback by Oster’s calculations. Asymptomatic kids, Hyde points out, “have the potential to be silent spreaders.” As one teacher wrote to Oster in July, “I resent my life being played with as if it doesn’t matter and all that matters is the children.”
The way Oster sees it, “we do all kinds of things that suggest that we allow for the possibility that people could die as a result.” Kids attend school during flu season, and people drive cars and have pools—all of that comes with a risk of mortality. “But that’s a very hard argument to make. It’s a very callous, economics-y sounding argument about the value of life,” she says. “Perhaps a more positive response is that there are some really large benefits.”
The ability to do a true cost-benefit analysis—for Oster or any of us—is hamstrung by the lack of comprehensive infection data from child-care settings. So Oster and her team at another of her projects, the website Covid Explained, began collecting their own data. “Part of it is, honestly, I’m looking to shame the world, the CDC, states, whoever, who are telling us it’s impossible to learn from this,” she says. “I’m a lady with a newsletter. You should improve your data-collection efforts.”
Oster was awakened at 5 a.m. on a recent Monday, as she is every day, by a vibrating band strapped around her ankle. (A regular alarm would disturb Shapiro, who sleeps for another hour.) She sent some emails, set out a plate of fruit for the kids, and set off for her running club’s twice-weekly track workout. She rediscovered the sport during the pandemic—“It’s like being back in high school cross-country except with more joint pain”—and now runs every day at 6 a.m., using it as her time to think.
After a morning spent juggling the kids and work and tweeting a screenshot showing that Reese Witherspoon had started following her, Oster installed herself in front of her laptop in her bedroom-turned-office at 1 p.m. Rhode Island Governor Gina Raimondo was delivering an update on the status of fall schooling. Oster’s children kept barging in. “You don’t understand,” she told them. “It’s very, very important that I watch what the governor is saying!”
Oster let out an actual cheer as Raimondo spoke: Most public schools in the state could reopen in person on Sept. 14, and private schools, such as the one Penelope and Finn attend, could do so immediately.
When I caught up with Oster two days later, she was beaming. “Today is amazing,” she said. “Finn went to kindergarten.”
As this story went to print, Rhode Island’s schools had managed to avoid mass outbreaks and stay open. Many other places haven’t been as lucky.
I’d been talking with Robert Weyant, an epidemiologist at the University of Pittsburgh. “I tend to be a cautious person,” he wrote in an email on Sept. 23. “It seems like waiting to reopen is the more prudent thing to do. But we do have a great natural experiment ongoing with some districts open and some not—so we shall see in the rather near future if opening is a good idea.”
That same day, Oster unveiled, with a software company and several national education groups, an expansion of the data-collection effort she’d begun over the summer. The National Covid-19 School Response Dashboard so far covers 1,006 schools across 48 states with 528,000 students and 54,000 staff. During the second half of September, the confirmed infection rate among kids attending in-person (full time or hybrid) was 0.13%. Among staff it was 0.24%. In a school of 1,000 students and 100 staff, that translates to 1.3 student cases every two weeks and one staff case every eight weeks. Oster is now working to identify patterns—are schools that don’t require masks seeing more infections?—and plans to alert districts so they can change behavior.
Oster knows she’ll get blamed if the reopening experiment ends in disaster. In that case, “the best I can do is say that I did something I felt was productive and helpful,” she told me. “If the result of having done that is that the policy direction I pushed was not right, at least I got the data to show that.”
It would be ironic, I responded, if her own dataset proved her wrong. “It’s true!” she said. “I think this data will be useful no matter what we show. But, yes, it would be ironic if I once again show myself to be wrong. That could be my thing! But I’m hoping not.”