Careful what you say in lecture: a tale of tweets, ice-storms in Quebec, and population ecology

While discussing age pyramids in my ecology class last week, I mentioned that there was a mini baby-boom in Quebec following the 1998 ice storm. In other words, after an extended period of time without electricity, more babies were conceived.  This is one of those ‘urban myth‘ stories for which I had no data to actually discuss whether this was fact or fiction, but it was mildly amusing, and certainly related to the discussion we were having about population ecology and the effect of the baby-boom generation on Canadian demographics.

I expected this story to stop there, but a savvy student in my lecture tweeted what I had said (yes, there are definitely pros and cons of being an active participant in social media, including twitter).  I was being called out, publicly, about my casual comment in lecture.  This forced me to look to the data and test my hypothesis that the birth rate in Quebec may have been higher after the ice storm of 1998.

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Data required?  Yearly population estimates of areas affected by the ice storm (i.e., numbers of females), and number of births in these regions.

Thankfully, these data were readily available.  However, not all data were tabulated in the same way by geographic region in the Province.  This meant that I had to narrow down the region to just the island of Montreal (thankfully one of the more populated parts of the province).    I took the number of births, divided by the number of females to get a per-capita rate of births per female per year in Montreal, and I looked at the years from 1997 through to 2000.

I predicted that if my hypothesis was true, birth rates would be higher in late 1998, therefore if data were collected properly, the ‘boom’ in births would likely be in that year (…or possibly in 1999).

Here are the results:

1997: 0.012 (babies born / female)

1998: 0.012 (babies born / female)

1999: 0.011 (babies born / female)

2000: 0.011 (babies born / female)

So, the data do not support the hypothesis that the ice storm resulted in a higher rate of births in Montreal.

Caveats?  There are a lot.  I have made quite a few assumptions, and my methods are partially flawed… I do expect students in my class to think about this…

Two other points to mention:

First, while searching for information about population-level effects of the ice storm, I came across a McGill press release about how babies born during the ice storm may be stressed later in life – Interesting!  And also somewhat counterintuitive to what I originally proposed in lecture.

Second, (and less related), we must be wary of these myths – they pop up all over the place (e.g. increase in births after the publication of Fifty Shades of Grey?), but without a more detailed look at the data, we must be careful what we say.  Thankfully the urban myth about mini-baby booms and power outages are debunked with some regularity.

In sum, I learned an important lesson. Careful what you say in lecture.

…and thank you to my student who forced me to look more carefully into the story of the ‘ice storm babies’


4 thoughts on “Careful what you say in lecture: a tale of tweets, ice-storms in Quebec, and population ecology

  1. Chris – although you may have eliminated the idea of a mini-boom based on yearly numbers. There are other measures – was there a “baby bump” 9 months after where typical child bearing demographic concentrated to that time of the year (9 months) without affecting annual? Maybe the couples most susceptible to creating pregnancy clumped to that time of the year?

    always good to call out urban myths of course!

  2. It’s good to be called out when public statements are incorrect, and the earlier the better. Just this week I have had two people point out errors on blog posts, which does not always happen (the pointing out, that is, not the errors…). I really do appreciate being corrected, and I wish people were less hesitant to do so.
    Being slightly embarrassed in the morning is better than the humiliation of knowing you’ve been walking around with your fly down all day!

  3. There may not have been a baby boom, but there were effects. Pregnant mothers exposed to the stress of the ice storm may have been stressed in ways that caused developmental fluctuations; this was measured using digit ratios down the road by my M.Sc. advisor (Pete Hurd) along with colleagues at Concordia (I think). He’s had trouble publishing the data, because no one believes it, but he can make a good case for there having *something* that came of it.

    • Thanks for the comment – interesting! Yes, I have heard of other measures health linked to things like major power outages, but I didn’t find anything it the primary literature (although, to be truthful, I didn’t do a full and comprehensive literature survey)…. something to investigate for a future blog post!

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