Should I sleep-train my baby? Should I go back to work? Is television going to fry her brain? Being a parent today can feel like a never-ending run of difficult decisions. There is no shortage of expert advice on which choices to make, but Brown University economist Emily Oster wants to offer something better than advice: information. Instead of advocating certain parenting practices, she aims to equip parents with the tools to make the best decisions for their unique circumstances, using her scientific training. In her new book, Cribsheet: A Data-Driven Guide to Better, More Relaxed Parenting, from Birth to Preschool (Penguin Press), Oster explains the principles behind an economist’s approach to decision making—weighing the costs and benefits, taking into account the particular constraints of the decision maker—and then presents the scientific evidence for the efficacy and safety of various practices, so readers can come to their own conclusions. The book is a sequel to her first tome, Expecting Better: Why the Conventional Pregnancy Wisdom Is Wrong—and What You Really Need to Know, which took the same approach to the questions that come up during pregnancy.

Scientific American spoke to Oster about where the parenting evidence is lacking, why it is sometimes hard to listen to the data, and what to do when your mother-in-law is just wrong.

[An edited transcript of the conversation follows.]

With thousands of books on parenting already out there, why do you think the world needs this one?

Most of the parenting books are about, “This is what you should do”—for instance, “Here’s how you sleep-train your kid.” By the time you’ve bought the book you’ve already decided to do it. But I don’t think there’s as much in the space of “Should I do that?” I tried to take a more objective look at the evidence and not write a book that says you should parent in this or that way.

There are many, many choices in parenting that the official guidelines have nothing to say about. The American Academy of Pediatrics is not in the business of telling you whether you should work outside the home or send your kid to daycare. I see this book as helping people think about many of the choices they face where their doctor isn’t going to be helpful or there’s a lot of stress around a decision.

Is there a parenting question you wanted to tackle where we really don’t have good enough data to answer it?

An example is screen time. There is a chapter on screen time, and there I present a bit of evidence, most of which is fairly reassuring. But there isn’t the kind of evidence you would want to answer most questions you may be wondering: Does it matter what kind of TV it is? With the iPad apps that say they’re educational—is that really true? There just isn’t any good evidence. The book confronts that, and it gives people a way to think about these questions.

For a lot of issues it’s just extremely difficult to answer these questions, given that the choices people make about parenting are made with a lot of thought and a lot of external constraints. In some cases, it’s hard to really imagine how you would do the research. For something like “What’s a good kind of daycare?” it’s hard to randomize kids to different daycares—good ones and bad ones—and see what happens. That’s not something we can do. Sometimes you just have to make a choice without having data, and that’s too bad or those of us who love data.

As a parent, has it ever been difficult for you to make a decision based on evidence, the way you would want to?

With many of these things, it’s very easy to write about them and see the decisions you should have made. But for me, breastfeeding my first kid was really hard. I had actually read a lot of the evidence, and I knew that some of the more grandiose claims about breastfeeding’s benefits were overstated. I knew this wasn’t as big a deal as people had made it out to be—but it was still a big deal to me. It was very, very hard for me to step back and say, “I need to give myself a break and not feel so bad about [giving up breastfeeding].” That was a place where I couldn’t step back from the emotions that I had wrapped up in this being successful.

And do you find that sometimes it’s hard to believe in the data, even though you’re a person trained to do just that?

There’s a reason I had a much easier time sleep-training the second kid than the first: Because when you’ve done it once, it is easier to convince yourself of the evidence—even though, of course, it shouldn’t be, and the evidence is what it is. The fact that you’ve seen it work once for your kid shouldn’t be important. But it is.

A big genre of parenting books seems to be comparing American parenting with other countries, and finding us lacking. Did you consider discussing research on American parenting vs. European parenting?

I also am a fan of that genre. There are many good things about those books, but the comparative stuff is so difficult. Okay, so French kids are different from American kids, but that could be for a billion different reasons. Okay, the Finnish don’t teach their kids to read until second grade or something. But Finland and America are different in so many ways. I think it’s very hard to learn much from these comparisons.

A big source of parenting conflict seems to be disagreements between, say, what your doctor tells you to do and what your mother-in-law tells you. Has a lot of the evidence on parenting changed recently?

With some of these things, we have learned more and evidence has evolved. Back-sleeping is a good example, where better evidence came in and we found out the recommendation to put your kid on its stomach to sleep was wrong. I think it’s hard when it changes in such a short time, in a generation. It can be hard to convince, say, your mother that the things she was told were not right. Saying, “that way of parenting is wrong,” or “you put your kid at risk,” is a hard thing for people to hear. That’s why there’s resistance to change among people who parented in one way 30 years ago.

Parenting can feel really complicated in this modern age. Do we have more decisions to make these days than previous generations did?

I definitely think people perceive that we are more obsessive about our kids, and thinking of every decision as super central—and that people used to be more chill about their children. But I’m not sure that our perceptions there are so clearly lined up with reality. When I was writing the book, I read Dr. Spock and then I read some of the series of books my grandmother had. In both of those, there’s a tremendous amount of angsty detail about how you’re supposed to do things. You don’t come away from that thinking, “wow, these people were so chill.” Maybe the recommendations were different, but it was the same long discussion.