Where to advertise a postdoctoral position to widen the diversity of applicants? I am planning to hire a postdoc (in mathematics), and have never done this before. My department is far from diverse. I have read that a good way to achieve a diverse pool of candidates is by advertising widely, including circulating them to special interest groups.
I can definitely see the benefit of this. Members of underrepresented groups may tend to be less &quot;well connected&quot; in the community and, as a result, the advertisement might have a harder time reaching them. At least, this seems to be part of it.
I would love to advertise widely, and specifically to organizations which will help me reach underrepresented groups. However, I am finding it difficult to find viable options for doing this... Many sites charge hundreds of dollars for each job posting. While I would love to post it everywhere, it doesn't seem realistic. The main things that I have come up with are:

Mathjobs (https://www.mathjobs.org). I expect that this will reach the largest number of interested applicants (the job is in North America). But this is really just the standard place to post things.
Association for Women in Mathematics (https://awm-math.org/). This actually seems like a really great option.
Distributing the advertisement through mailing lists dedicated to my area of mathematics.
Some professional societies in mathematics allow members to post jobs (I think).
Advertising the job at the end of research talks (although, it doesn't seem to be that commonly done in my area, so it might be awkward...).
Advertise to colleagues and ask them to spread it by word of mouth.
Posting to social media? Although I am a bit wary of this.

Apart from the AWM, I don't really see how any of these will benefit members of underrepresented groups specifically, and, even the AWM is mainly targeting one group. Does anyone have any other ideas? Suggestions?
This post focused mostly on where to advertise the job, but I would also love to get input on all aspects of achieving a large and diverse pool of applicants! Please feel free to share any advice you have.
https://jobrxiv.org/ and twitter although I don't know how much math people use either. For my bio-related field they're pretty good.
You'll probably get plenty of diversity in your applicant pool but you'll end up removing most of it when you filter for prestige PhD institutions and advisors. You should try to remember that URMs from second tier PhD institutions are just as smart in aggregate as the population from Stanford or whatever, but are likely to publish worse and have fewer opportunities. Evaluate them based on who's outperformed for their grad environment and in general you'll probably have a bunch of applicants you wouldn't have otherwise considered. (This is also useful for identifying the halfwits from Harvard who have underperformed despite every possible advantage - don't hire them).