Parents these days are inundated with advice—on everything from breastfeeding to sleep training, from childcare to screentime—almost all of it purportedly evidence-based. Who better to sort the wheat from the chaff than Emily Oster, an economist who distinguishes “the good studies from the less-good ones” for a living? She did just that in Expecting Better, a book about pregnancy that, like Cribsheet, leads with the following premise: No expert, even Oster, can tell you what’s right for your family in most instances. Instead, she summarizes what high-quality science reveals about the risks and rewards attendant to any given choice, and describes a way of weighing those pros and cons in combination with your own preferences. “The data is the same for us all, but the decisions are yours alone,” she reminds.
Here’s an example of how that goes in the context of having your baby sleep in your bed:
The finding that co-sleeping carries a small risk even if done as safely as possible is largely consistent across studies…. Among families with no other risk factors, roughly 7,100 of them would have to avoid co-sleeping to prevent one death….
[S]ince the data suggests that there is some risk to sharing the bed, and possibly also to having your child sleep in their own room, we may conclude the absolute safest thing is to have your child sleep in your room in their own bed for these first few months.
Yet this setup may not work for your family. Let’s imagine that your preference is to share your bed with your infant—maybe you think it will be easier to breastfeed, or you simply want to have the baby close.
If this is the case, there is a strong temptation to dismiss the evidence on risk. It is easy to find parenting sources that point to one study that doesn’t show significant impacts of bed sharing and say it proves there is no risk. This is not a rational way to make this decision. If you want to do this right, you need to confront the idea of risk, think about how to make it smaller (if you can), and then think about whether the (minimized) risk is one you are willing to take….
[T]he evidence suggests that bed sharing [for sober nonsmokers with full-term infants] increases the risk of death by 0.14 per 1,000 births. The death rate from car accidents in the first year of life is around 0.2 per 1,000 live births. The bed-sharing risk is therefore a real one, but it is smaller than some of the risks you are likely taking regularly.
Now, that excerpt might leave you thinking Cribsheet is exceptionally dry, and it is, but not in the bad way. Oster writes with precision and an almost British wit, a style that truly delights once one gets used to it: “In the first days and weeks after your baby arrives, you will experience a wave of hormones. Most women find they are emotionally sensitive during this period. This is not, for example, the time to watch the first fourteen minutes of the movie Up.” Here’s another taste: “One trial shows some benefit of something called gua sha therapy, which involves scraping the skin to produce light bruising. Gwyneth Paltrow swears by this, so take what you will from that.”
Wry and understated is not the norm for parenting books, nor is Oster’s awareness of—and comfort with—her own neuroses, something more reminiscent of David Sedaris or Jenny Lawson (e.g., “I have many notes from the first months of Penelope’s life about her rolling ability (very early rolling to the left, but poor rolling to the right)”). The resulting tone strikes just the right balance for a brilliant person seeking to communicate effectively with the masses: “There is another type of evidence, one that you see a lot on the internet. I’d refer to this as … ‘it happened once to my friend’ evidence. You know: ‘My friend didn’t vaccinate, and her kid is super healthy!’ Here is what we learn from this: nothing.”
Cribsheet is also exceedingly well-organized, complete with a “Bottom Line” synopsis at the end of each chapter.
That’s not to say the book is flawless. Oster sets out to provide “a basic, data-derived map of the big issues that come up in the first three years of being a parent,” but her success is necessarily confined by a few limitations: (1) research constantly evolves and she has access only to that which has been published as of her release date (data that came out after Expecting Better called one of its core conclusions into question), (2) the extent to which her methodology is the right one (figures in the field of public health have criticized her for examining studies using an economist’s eye rather than their own set of standards), and (3) her ability to dig up all relevant information. I’ll focus on the third of these here.
Oster acknowledges that “the problems get more varied as kids get older, and much less amenable to data analysis.” But she still chooses to tackle toddler discipline, and there she falls short. To explain how, it’s important to look at a topic she nails: TV watching. Oster takes what she calls “a Bayesian approach,” incorporating logical reasoning based on background knowledge about how the world works when existing data doesn’t paint a full picture:
There are only thirteen or so waking hours in the day for kids. If they spend eight of those hours watching TV, there is not enough time to do pretty much anything else. It seems very unlikely that this won’t have some negative impacts. On the other hand, it is hard to imagine that watching an hour a week of Sesame Street or Dora the Explorer will lower your child’s IQ, or have much of any effect on them in the long run. You can subject the iPad to similar logic. A two-year-old who is on an iPad all day: likely bad. A half hour of math games twice a week: probably not bad.
Finally, our intuitions should be informed by the economic idea of “opportunity cost of time.” If a child is watching TV, they are not doing something else. Depending on what that “something else” is, TV watching may be better or worse. Many studies of this emphasize that (for example) your kid can learn letters or vocabulary from Sesame Street, but they are better at learning those things from you. That’s almost certainly true, but … [i]f the alternative to an hour of TV is [instead] a frantic and unhappy parent yelling at their kid for an hour, there is good reason to think the TV might actually be better.
Here, Oster trounces other commentators on screentime, using fair inferences and arguments waged on both sides of the debate to reason toward a likely ideal: low screentime with a high-value alternative activity. Only after that step does she bring reality into the calculus.
But when it comes to discipline, Oster fails to do this. She profiles several “rewards and punishments” programs and concludes that they “have been shown to improve children’s behavior,” without factoring in possible externalities of inducing compliance in this fashion. Many parenting commentators point to social science research on fostering intrinsic motivation, independence, and healthy self-image, and say using natural consequences rather than punishment produces desirable behavior without undermining autonomy and trust. Oster takes the opposing view as a given: “[K]ids … need to be punished sometimes.” Stickers, M&M’s, and time-outs have also been called into question by child development experts as means of control that backfire in the long run, but she refers to the practices unquestioningly. (Contrast Oster’s treatment of baby-led weaning which catalogues many of the theories cited by proponents and opponents of the practice prior to concluding that the data is inconclusive.) She rounds out the section by saying spanking has been shown to be counterproductive “so if hitting is the alternative, then one of these programs is probably worth a try,” but it’s unclear why that would be the bar.
There are other blind spots. The section on crying, for example, doesn’t state that some babies do so because they need medical attention. To be fair, this isn’t just Oster’s problem. Lots of parenting commentary meant to calm can lead parents of sick babies to try to tough it out at home for too long.
That said, stress reduction is one of Cribsheet’s great strengths. “There are lines you shouldn’t cross with young children,” she writes: “but there are many more gray areas.” Making it clear that there’s often no one right way to do things is likely to diminish new parents’ anxiety considerably. Conversely, so too can definitive, unequivocal advice like the following:
- Your toddler or young child does not generally need a multivitamin.
- Although antidepressants are passed through breast milk, there is no evidence of adverse consequences.
- Despite the warnings, there is simply no evidence that the use of pacifiers impacts breastfeeding success.
- There is no need to pump and dump.
- Across virtually all studies of sleep location, the one thing that jumps out as really, really risky is babies sharing a sofa with an adult.
In Cribsheet, Oster offers all this and much, much more—like debunking the “no sex until six weeks postpartum” thing, a rule she says “appears to have been invented by doctors so husbands wouldn’t ask for sex.” You might want to wait, deciding that dealing with the vaginal dryness caused by breastfeeding (an Oster fact) is a burden not fully mitigated by the risk of a decline in marital happiness from less sex (a second Oster fact). “Not everyone is going to make the same decisions,” she says, “and that’s okay.”
It’s also okay to both point out Cribsheet‘s limitations and call it a job exceptionally well done.