Earlier quoted context omitted.
A PhD in maths is _incredibly_ valuable. Anything abstract algebra related, and the likes of the NSA are all over you. Anything numerical analysis related will find plenty of opportunities in finance, and the industry just calls statistics specialists "Data Scientists".
Yeah, to be fair, my perspective is from Canada, which I probably should have mentioned. I mean, we do have the RCMP and Bay Street, but I don't think it's comparable (in number of positions, salaries offered, etc) to NSA and Wall Street.
In addition, outside of the RCMP, various ministries of the Canadian government could need the skillset too (Statistics Canada being the one that first comes to mind, though any teams that do economic analyses could benefit from someone with the background).