I had a lot of fun this week reading through Emily Oster’s book Expecting Better: Why the Conventional Pregnancy Wisdom Is Wrong in preparation for my Insights piece tomorrow on childhood obesity and pregnancy.
For anyone pregnant, planning on getting pregnant, knows someone who fits either of those categories, or just really likes fun applications of economics in the real world, I highly recommend this book. I found it an interesting and informative use of economic tools and reasoning to navigate the pregnancy guidebooks out there (don’t worry Mum, I was reading it for academic purposes only).
But then I came across this critique from The Daily Beast, and it has really irked me:
It turns out Oster isn’t relying on interviews with medical professionals or public-health experts. She doesn’t reach her conclusions after tons of conferences or meetings with scientists. She’s combed through and “debunked” the pregnancy research—personally, as an economist. And that’s a problem.
The critic’s main argument seems to be that medical professionals would never dream of straying outside their field of expertise, so how dare economists?
Such views are probably not unheard of, and it does raise an important question: why should anyone trust Oster, or in fact any economist on public health issues? Why trust economists over medical professionals or public health academics who have years of experience within the sector? As we at the Initiative delve into our own research on public health, it’s a question worth tackling early.
I can think of a few areas where economists add value:
Economists don’t write “personally” on the subject (whatever that even means). They employ statistical and econometric tools to the existing literature to determine robustness. That is, many economists like Oster examine the literature and evidence produced and used by medical professionals and scientists. You don’t need to attend numerous conferences or meetings to get the skills to read a health study. Economists employ their skills to ascertain what a health study says it will achieve, how it set it about doing it, and whether it has actually achieved what it said it did.
Now, that’s not to say that economists are the only ones who can do this. Anyone with a statistics background could apply that lens. But from the many public health studies out there (and Oster’s scrutiny of pregnancy studies only covers a small portion of the broader public health category), it is clear that too many studies are entering the public domain without proper reliability checks.
More importantly, those studies are influencing real medical advice and even government policy.
So what would an economist look for? Well, proof of causality is one factor. Do the results of a study prove that one thing without a doubt caused an event to occur? Or are the two events simply correlated? Are there other explanatory factors that could have caused the outcome? Is the direction of causality right?
It is also important to look at the size of the effect, and the likelihood of risk. If you are only dealing with tiny percentage differences in results, and the likelihood of an undesirable event is incredibly small, then that should play into individual decision making. Now, Oster has copped a lot of flak from critics saying that any risk is too much risk when it concerns an unborn child. But she puts it this way:
People ask, “Why take the risk?” since there is no benefit to the baby. But this ignores the fact that we are always making choices that could carry some risk and have no benefit to the baby. Driving in a car carries some risk to your baby, and your fetus does not benefit from that vacation you took. Or they ask, “Is it so hard to give up drinking for nine months?” The answer is, of course, no, but because you might enjoy the occasional beer, it seems worth at least asking the question about the risks.
These are, of course, only two things among many that economists may look at when assessing the reliability of public health studies. Others include looking out for common mistakes in cost benefit analysis, looking at the assumptions made in the methodology, and taking into account behavioural effects such as substituting one undesirable activity for another. I may cover other factors to look out for in future blogs, and they’ll definitely be considerations for our coming research report.
But for now, I’d just like to conclude by saying that economists should not be discounted from the public health space simply because they do not have a medical background. Many of the skills used to properly interpret health studies are transferable across fields.
And if the authors of these reports have nothing to hide, they have nothing to fear, right?