Cribsheet: A Data-Driven Guide to Better, More Relaxed Parenting, from Birth to Preschool

Award-winning economist Emily Oster tackles a parenting challenge: decision-making in the early years of parenting.

Home » Book Summaries » Cribsheet: A Data-Driven Guide to Better, More Relaxed Parenting, from Birth to Preschool

kk: From The Parent’s Club, I’m Karsen Kolnicki. This is your briefing.


kk: Today, we’re discussing *Cribsheet: A Data-Driven Guide to Better, More Relaxed Parenting, from Birth to Preschool*. Written by Emily Oster.

In her previous book, Expecting Better, award-winning economist Emily Oster spotted a need in the pregnancy market for advice that gave women the information they needed to make the best decision for their own pregnancy.

In this latest title, Cribsheet, she tackles an even greater challenge: decision-making in the early years of parenting.

kk: Vincent Phamvan on the key takeaways [pause] and what you need to know.


kk: Vincent, do you hear about new parents coming across conflicting advice from doctors, family, friends… and even strangers on the internet?

vp: Definitely. Early on, parents are told that they have to make certain decisions around feeding, sleeping, and schedule, or else they risk “doing it wrong.”

There’s a lot of rules out there, sometimes even multiple rules. So Oster is really tackling this problem in this book. She’s an economist by trade, so Oster finds that when you look at the data, the conventional advice doesn’t always hold up.

She debunks many myths around breastfeeding, sleep training, and potty training.

kk: Economics is all about the science of decision making, so is Cribsheet a parent’s guide to noise and misinformation in the early years?

Yes, Oster is a trained expert—and mother of two—and she really helps empower all of us to make better, less fraught decisions to help stay sane in the years before preschool.

kk: Okay, so what is a cribsheet?

vp: Well, a crib sheet is a small piece of paper that students use to write down information to use during a test in school instead of memorizing it. I remember growing up, a lot of my friends would keep their crib sheets inside the label on a water bottle so they could read it when the water bottle was on their desk.

This book, though, acts as a crib sheet for parenting. If only parenting could be that easy, a small piece of paper that helped you make parenting decisions.

It’s a little odd to have this book written by an economist instead of a pediatrician or a child psychologist, but the book actually makes a lot more sense than you might think.

kk: So what are the types of parenting decisions where there is conflicting information?

vp: Well, if you’re the parent of a newborn baby boy, one of the first decisions you have to make is whether or not you should circumcise them. Another decision is whether you should sleep in the same room as your newborn.

Often when you seek out opinions from friends, family members, doctors, or online articles, there’s completely opposite advice. Some people say you should definitely circumcise, and others say that it’s dangerous and completely unnecessary.

And of course, both sides come armed with facts for their side with peer-reviewed studies and biological facts and personal anecdotes. It can be very confusing.

Another early decision is whether or not to breastfeed. In fact, for mothers, some people outright judge mothers if they resort to feeding their baby with formula.

Taking care of a baby for the first time can be stressful enough, and the conflicting advice doesn’t help when you’re sleep-deprived and exhausted.

kk: And the stakes are pretty high on these decisions because you’re trying to ensure the survival and welfare of your little one.

vp: Right, the person who is suddenly the most important person in your life. What’s unique in this book is that if you approach these questions like an economist, you’ll see that the short answer is that there are never any “right answers”. Oster says that in many cases, it’s actually the wrong way of framing the question in the first place!

kk: So how exactly does economics play into decision making as a parent?

vp: Well, economics often ask: given the decision between two services, how do you decide which to purchase?

For economists, this comes down to a few factors. There are costs and benefits to the choices, which are called “inputs.” These inputs can be monetary and non-monetary.

If you’re making a decision between putting your child in daycare or hiring a nanny, the nanny is the more expensive option, so daycare is likely the better choice.

However, if you are wealthy, then the degree that money matters to you may differ from that of someone else in the middle class or without as much disposable income.

But the other side is if you’re a middle-class person and you value your social opportunity, then that may be a non-monetary input that is worth giving up the cost of hiring a nanny.

So Oster argues that from an economic standpoint, there’s no single right decision for everyone. One decision can be right for one person, and another decision can be wrong for another. It all depends on people’s personal preferences and circumstances.

kk: But if there’s no right answer, then how would you have a crib sheet or a cheat sheet with the so called right answers?

vp: Well, there may not be a single right decision for every answer that a parent needs, but there’s a general framework for how you can approach the decision making.

To start, you can identify the costs and benefits associated with the choices in front of you. For example, going back to work or staying home with your child. Start by looking at the costs and benefits of each choice.

This will likely depend on your priorities. One view is if you are predominately focused on your baby, then you may be wondering about the impact of the decision on the child’s development and future adulthood.

But if you have yourself in mind, then you may be considering the impact on your own happiness and success.

These are subjective, and the answers depend on how you feel about being a parent. A third viewpoint could be on your family’s budget.

kk: So you would have to budget out how much income you’d earn if you went back to work?

vp: Precisely. It’s only after you determine the answers to all these different versions of the original question, and take into account your personal preferences and circumstances that you can make a decision.

kk: Wouldn’t an economist’s decision-making framework be cut and dry with determining the best financial course of action?

vp: You would think so, but in practice, it’s just more complex in real life. For example, if you don’t have a relative to look after your baby and you live in a country without free childcare, then you’d have to pay for daycare or a nanny to go back to your job.

That means if you have a low salary and high cost of childcare, you may actually lose money by going back to work.

If your income is greater than the cost of childcare, going back to work will improve your finances, but not by as much as you’d think. If you make $25,000 a year from going back to work and childcare costs $18,000 a year, then you’d only net $7,000 a year.

If you need that $7,000 or you love your job, then this might make sense. But if you don’t need it, and you place more value on spending time with your child, then $7,000 might not be worth it.

kk: How would this apply in a non-monetary approach to the decision making framework?

vp: In weighing potential risk and advantages of choices, in theory, it should be a pretty rational process. Draw a line down a sheet of paper, write the risks on one side and the advantages on the other side.

In practice, our emotions can make things messy. The reason is that the idea of putting our children at any risk often provokes a knee-jerk reaction.

For example, if you make a decision to share your bed with your baby, or co-sleeping, you’re putting your child at risk. You could roll on top of them, or they can get tangled up in your sheets and suffocate. The research shows that there’s a higher risk of Sudden Infant Death Syndrome, or SIDS.

kk: That doesn’t sound good.

vp: No, it’s not. So when you hear this, the decision should be pretty clear, you shouldn’t share a bed with your baby.

But the risk of infant death from car accidents is considerably higher than that of co-sleeping: 0.20 versus 0.14 per 1,000 births, respectively.

There’s still a risk though, 0.14 per 1,000 births, but some risk is unavoidable in life.

kk: Are there benefits of co-sleeping?

vp: Well, the main one is for the parent. If you’re a breastfeeding mother, and your baby wakes up in the middle of the night, you don’t have to get up to feed him. You can just roll over, nurse, and then go back to sleep. So you’d get more sleep as a result.

Sleep deprivation is pretty common with new parents, which can lead to depression, so that’s a pretty big benefit. But the decision on if that outweighs the risk of co-sleeping is purely a personal decision.

kk: What about the scientific research?

vp: Well, Oster shares that much of the research centers around collecting data about which parenting practices correlate with outcomes in children.

So there are studies that correlate breastfeeding with children’s IQs. They find that breastfed children tend to have higher IQs than non-breastfed children. Seven points higher, actually.

kk: There’s the old saying though that correlation doesn’t necessarily equal causation.

vp: That’s right. Just because the two things are found together, doesn’t mean that one causes the other. There could be additional, confounding variables involved that are common to both breastfeeding and IQ. For example, in most developed societies, women who breastfeed tend to have higher IQs, incomes, and educational levels than women who don’t.

If you’re a researcher, you can try to adjust for these variables. And after adjusting for it, some researchers still find a correlation between the two but there’s still skepticism from others.

kk: So then reality is pretty complicated because there are so many variables involved.

vp: That’s right, if there was a correlation between breastfeeding and IQ decreases with each additional variable you adjusted for there’s two options: the possibility that you’ve adjusted for every conceivable variable and there actually is a connection between the two or the possibility that there are simply more variables than you could think of, and that would decrease even further to the point where the correlation disappears entirely if you could think of all the variables.

Oster argues that it’s the latter.

kk: So how do parents keep their decision-making processes evidence-based?

vp: That brings up a good point, that you should weigh not only your decisions but also the evidence that informs those choices.

To conduct good research, you’d have to recruit a large number of mothers and randomly split them into two groups: a treatment group of mothers who breastfeed and a control group of mothers who don’t.

Because you’ve randomized which mothers are in which group, they would tend to have the same characteristics on average between the two groups. The only difference would be whether or not they breastfeed. Then you could test for this one variable alone. If you find a correlation, then you can be relatively confident that there’s an actual casual link between the two.

The larger the group is, the more true this would be. The author shares that there has only been one large-scale randomized controlled trial conducted about breastfeeding. It established only two significant links between breastfeeding and child health outcomes: a four-percent decrease in diarrhea and a three-perfect reduction in skin rashes like eczema. It looked at other factors and didn’t find correlations in boosting children’s IQs.

kk: What are the other methods of research?

Right behind this gold-standard of research are observational studies, where you collect a bunch of data about both breastfeeding and non-breastfeeding mothers and compare the two groups. The best ones compare siblings from the same family where one is breastfed and the second child wasn’t.

And the last method to conduct research is a case-control study, where you go out and look for children who exhibit the same outcomes or symptoms. Then you try to find all the things they have in common.

After adjusting for the confounding variables, you see what you have left to try to identify a casual connection.

In 1998, a then-doctor named Andrew Wakefield conducted a case-study with 12 children who exhibited symptoms of autism. Each of them had been given a vaccine for measles, mumps, and rubella. He alleged a casual connection between the symptoms and the vaccine, which sparks the anti-vaccine movement.

Unfortunately, case studies are far more problematic than even very small observational studies. The data of case studies can be muddied by unthought-of confounding variables and the differences between people being studied.

kk: So in a larger study with a larger sample size, this wouldn’t be as much of an issue?

vp: Correct, the difference is not a big deal with a sample size of thousands of mothers or babies. But when the sample size is just 12 children, it’s just too small. In this case, Wakefield’s study was small for a reason. He purposefully selected children whose circumstances supported his conclusion and excluded children who didn’t. He falsified his data.

kk: So it’s best to trust the findings of well-conducted randomized control trials with observational studies.

vp: Yes, and Oster advocates approaching other research with some healthy skepticism.

kk: It sounds like the key takeaway from this book is that in the first few years of your child’s life, there are many factors that go into decision making. This could be impacted by circumstance as well as personal preferences. The other considerations are potential cost and benefits to the child, yourself, and your family. And while weighing these factors, you can be informed by scientific research if it is well-conducted randomized control trials and observational studies, but skeptical about case-control studies.


kk: That’s it for your briefing. I’m Karsen Kolnicki. See you next time.


With Expecting Better, award-winning economist Emily Oster spotted a need in the pregnancy market for advice that gave women the information they needed to make the best decision for their own pregnancies. By digging into the data, Oster found that much of the conventional pregnancy wisdom was wrong. In Cribsheet, she now tackles an even greater challenge: decision-making in the early years of parenting.

As any new parent knows, there is an abundance of often-conflicting advice hurled at you from doctors, family, friends, and strangers on the internet. From the earliest days, parents get the message that they must make certain choices around feeding, sleep, and schedule or all will be lost. There’s a rule—or three—for everything. But the benefits of these choices can be overstated, and the trade-offs can be profound. How do you make your own best decision? 

Leave a Comment