In the last month I have hired 4 people in specialist technical roles. I reviewed 15 CVs. All were from men. No women applied.

There is clearly something filtering women out. There is something deep in the supply chain of labor (by which I mean education) which results in women being siphoned off long before they hit my company's diversity and inclusion policies. I believe these policies are reasonably effective at tackling unconscious bias, but they are unable to affect the underlying talent pool.

My personal theory is that specialisms are risky (good pay if you can find employment, no pay if not), and men are more likely to take risks than women. There is research to support the latter point. Casual googling digs up this for example: https://www.researchgate.net/profile/James_Byrnes2/publicati...