[WhoIsSatoshi]

The title of the article glosses over one significant fact: You cannot know the pregnancy rate at the precise moment from (1) folks who do not know, (2) folks who will abort or lose the child (worsening economy, loss of job, stress...) (3) folks who do not report. It can be argued that you can abstract those cases out, but the useable data becomes extremely blurry as the early months of a pregnancy are the riskiest ones for the birth.

In hindsight, looking at the recorded birth and subtracting 9 months will give you a clearer picture but by then better indicators of recession in progress might have been more readily observable.

Nevertheless - I find the idea fascinating as the birth of a child is one where individuals have to take into account a lot of things and internalize/assess the situation for the immediate future beyond what folks want to hear or believe.

What I wonder about is the impact of those lost births on future economies (20 years later?) and/or what the impact is on the recovering economy.

[andrewla]

From the paper (preprint found here [1]), you are correct in how they reconstruct this information. They use birth data (including estimates of gestation period) to derive the pregnancy rate at a moment in the past. They also attempt to compensate for miscarriages and abortions.

I think your central conclusion is sound, though, namely that this cannot be used to predict the future because there's no reliable data source to give the pregnancy rate in the present.

On the other hand, it might be possible to show that even excluding your (1), (2), and (3), it would still make a reliable predictor. But I'm not sure that there are datasets that would allow any insight even into the number of reported pregnancies. Potentially pharmacies would have access to rudimentary proxies in the form of sales of pregnancy tests, or inverse proxies in the form of sales of contraceptives. Large companies might have information on parental leave, but in the lead-up to a recession, you might have the confounding variable that people are losing their jobs at a higher rate, leading to a direct correlation that might overstate the phenomenon.

[1] https://www3.nd.edu/~kbuckles/BHL_fertility.pdf

[olympus]

Not to mention that if you rely on estimating pregnancy rates by taking birth rates and then shifting backwards nine months, you have lost three quarters of time, and thus there is no way to use this data to predict a recession even if pregnancy rates do precede a recession by three quarters. So it's fun to look at, but ultimately useless for forecasting if you can't get real time pregnancy rates instead of waiting nine months.