Cecily Kane has been crunching the numbers and scouring the contents pages of short fiction outlets for several months and an updated report on the state of speculative fiction by black writers is out: https://firesidefiction.com/blackspecfic-2017
The original report resulted in a lot of defensive reactions from some editors of magazines. The fact of clear numerical underrepresentation was taken by some sections of short fiction publishing not as a call for people to do better but as an accusation of specific and conscious discrimination*. Those kinds of reactions are missing the point. The new report expresses the issue succinctly:
“The field is segregated, and whether that’s due to variable submission rates, variable acceptance rates, and/or other factors, the data expose a clear instance of structural racism.”
The under-representation of black writers will have many proximate causes but collectively they amount to a systemwide bias. Many of the factors in that bias will be external to fandom specifically and arise out of socioeconomic biases in wider society. BUT that doesn’t remove our moral responsibility to do better.
The good news in the report is that while overall levels of representation are low, they have improved and much of the improvement has been due to new writers being published. Notably several magazines have managed to publish black writers at a rate close to or greater than the proportion of black people in the US population (13%). Those outlets are Apex, Book Smugglers Publishing, Fireside Magazine, Strange Horizons, and Uncanny. In addition to those Fiyah magazine began in 2017, a magazine dedicated to Black speculative fiction.
*[on top of that, of course the Sad and Rabid Puppies reacted in pretty much the way you might expect:
The commanlity between the Sad Pup reaction to the 2015 report (published in 2016) and the reaction from less canine sources was the same confused ideas that if there are racist outcomes then there must be an overt ideological racist and hence that the report was flawed because it hadn’t shown that editors of short fiction outlets were maliciously discriminating against black people. The report, of course, never claimed any such thing.]