Bad Statistics and the Gender Gap
So there’s an article in Scientific American called How to Close the Gender Gap in the Labo(u)r Force (I’ve added a `u’ to `Labour’ so that it can be understood in the UK).
I was just thinking the other day that it’s been a while since I added any posts to the `Bad Statistics’ folder, but this Scientific American article offers a corker:
That parabola is a `Regression line’? Seriously? Someone needs to a lesson in how not to over-fit data! It’s plausible that the orange curve might be the best-fitting parabola to the blue points, but that doesn’t mean that it provides a sensible description of the data…
I can see a man walking a dog in the pattern of points to the top right: can I get this observation published in Scientific American?
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In the Dark 
April 3, 2019 at 10:04 am
What is the difference between an economist and an astrologer?
The astrologer won’t ever tell you that the Sun will rise in the west tomorrow morning, and never set again.
April 3, 2019 at 1:09 pm
Bulllshit is too kind a term, because bullshit is daft and wastes time but is not malign.
I have been predicting for two decades that the new Humanities postmodernists will eventually come after the scientists on campus. The latter mostly do not understand the intensity of the matter and will lose unless they are prepared to fight hard. Meanwhile, it might be best to go to Caltech or MIT or some place of higher education in the sciences that does not have Humanities faculties.
April 3, 2019 at 3:07 pm
We should go back to the good old days when all Humanities professors were Marxists!
April 3, 2019 at 3:45 pm
Scientific American should know better. I thought there must be some misunderstanding, but upon reading the article it appears that they meant exactly what they said.
Here is an article from the research literature that reaches this conclusion based on different data:
https://www.researchgate.net/publication/285566408_Female_labor_force_participation_in_developing_countries
For those who can’t or don’t care to access the full article, here’s the relevant figure:
It looks to me like their data set actually does have some variation — that is, the parabola is a better fit than a constant would be — and the article is reasonably forthright in saying that the evidence is weak. My chi-by-eye says that, based on the points plotted in this article, the decline at the left is real, but the rise at the right may not be.
April 3, 2019 at 4:36 pm
To be really convincing they need to take the Fourier Transform.
April 3, 2019 at 8:40 pm
I think I’d do a Bayesian evidence calculation. Compare the model y = constant with linear, quadratic, etc., and ask whether the Bayesian evidence favors anything but the simplest model (i.e., whether the improved goodness-of-fit is enough to justify the additional complexity of the model).
April 8, 2019 at 8:19 pm
“Scientific American should know better.”
SA has seen a sad decline in quality over the past several years.
April 10, 2019 at 1:27 pm
Or they could have done a bootstrap or some other cross-validation or some other cursory overfitting checks. They could have compares the linear model with theirs based on some information criterion to see if the additional parameter is justified by the variance it explains. There are certainly more I haven’t thought of.
I don’t dare read the article to find out if they did any of that.
April 3, 2019 at 5:05 pm
Ummmmm….
http://www.hss.caltech.edu
and
https://shass.mit.edu
April 4, 2019 at 2:44 pm
My more important point is that this is a slow-burn crisis of existential magnitude for science in our universities. The Humanities postmodernists hold a worldview that is totally incompatible with the one upon which science is based, and they are slowly outflanking scientists in positions of power inside our universities. You will be aware of the ‘science wars’, if only from parodies such as Sokal’s and after, and the position has only worsened since; but academic scientists either just get on with their research or they give up, after challenging the Humanities worldview and receiving flack and realising the magnitude and intensity of the counterpush necessary. This is not going to end soon, and as things stand it is not going to end well. It is also largely a battle within the Left: between old Left (modernist university scientists) and new Left (the postmodernist humanities). In this battle the old Left would do well not to be scornful of non-Leftist allies who also deplore postmodernism, for the greater rift is between postmodernism and everything else.
April 4, 2019 at 2:53 pm
Reblogged this on Symptoms Of The Universe and commented:
The exchange with Alessandro Strumia rumbles and lumbers on in the comments sections of previous posts, while over at his “In The Dark” blog, Peter Coles highlights that credulous over-interpretation of gender gap data is not the sole preserve of aggrieved and ideologically-biased particle physicists…