Entirely Failing To Understand The Gender Variability Argument In Employment


An interesting piece of research here. Looking at variability by gender. The standard finding, that male variability is greater than female is confirmed. Excellent, so what’s the problem here? Well, that they’ve rather looked at the wrong side of the equation to determine what this means for higher education and career choices.

They have not, unlike so many others, fallen into the trap of thinking that men are better than women at, say, engineering. That’s not even the claim that’s more usually made anyway. Rather, the claim is that given the difference in variability then you’re more likely to find more men with the attributes necessary to perform at the very top and of such a subject, just as you’re more likely to find more men among the entire dullards – something which accurately describes me when considering engineering.

Yes, it’s the Larry Summers argument.

So, they’re on board with the basic contention but then:

Gender differences in individual variation in academic grades fail to fit expected patterns for STEM


Fewer women than men pursue careers in science, technology, engineering and mathematics (STEM), despite girls outperforming boys at school in the relevant subjects. According to the ‘variability hypothesis’, this over-representation of males is driven by gender differences in variance; greater male variability leads to greater numbers of men who exceed the performance threshold. Here, we use recent meta-analytic advances to compare gender differences in academic grades from over 1.6 million students. In line with previous studies we find strong evidence for lower variation among girls than boys, and of higher average grades for girls. However, the gender differences in both mean and variance of grades are smaller in STEM than non-STEM subjects, suggesting that greater variability is insufficient to explain male over-representation in STEM. Simulations of these differences suggest the top 10% of a class contains equal numbers of girls and boys in STEM, but more girls in non-STEM subjects.

Ah, and now it’s the economics they’re getting wrong, not the biology.

One approach to this would be to follow the James Damore path – or Simon Baron Cohen if you prefer. It’s not that men are better – as above – nor even that there are more men who are better. Rather, there are more men who are interested. Given that we do make life choices along the lines of what interests us there we are. Many will find this unconvincing.

So, instead, let us consider comparative advantage. The only non-obvious and non-trivial finding in all of the social sciences. Yes, this is normally thought to be about trade but it’s wider than that. And it is almost always misunderstood too, confused with absolute advantage.

Absolute advantage is that I’m better than you – what at doesn’t matter but I’m sure I could find something I am better than you at if I really tried. Well, hope so – and therefore I should be doing this and you something else. Comparative advantage is much more subtle and the best way to think of it is as not referring to other people at all. There are a number of talents I have – OK, a number of lack of talents – and a number of things I could be doing. I should do whatever of the things those talents make me least bad at. If we all do what we’re least bad at and trade the results then there will be more of everything and we’ll all be better off.

Comparative advantage – the comparison is to what I can be doing. It is not possible therefore for anyone to have greater comparative advantage at everything – cooperation and trade will always make me better off.

OK. So, now look at those variability results again. Women are often better – on average are better – than men in STEM subjects at least at low levels of academe. Yet women end up off in the arts and humanities rather than STEM. Our finding here is that women are better better than men at the arts and humanities stuff at these lower levels of academe. If we all act on comparative advantage then that’s where we should be too. Being better better at something is having a comparative advantage. Women are better than men (as always, this is averages, nothing to do with any individual at all) at engineering and better better than men at non-engineering. Thus the women should – on average – be doing the non-engineering while we leave the men to do what they’re not so bad but still worse at.

The fun of this is that this paper tries to point out why the conventional explanation of male STEM dominance cannot be right. But their finding gives us a perfect explanation of why it does exist. For exactly the reason that a rainy and cold Lancashire made the cotton underpants to be worn by the Portuguese labourers drenched in sunshine who grew the grapes to make the wine – comparative advantage.

Women are as good as men at engineering, women are better than men at not-engineering, therefore men should be doing the engineering. Comparative advantage is non-obvious and non-trivial and it is also true.

My own prejudice is that it’s only now that engineering is relatively well paid that this has become a societal problem. But then that’s probably mansplaining.