Mammoths of the Great Plains is part of what PM Press call Outspoken Authors, and each feature a novella, an essay, and an interview, as far as I can tell. Other authors in the series include Ursula Le Guin, Michael Moorcock, and Terry Bisson, the latter of who provides the interview in Arnason's book. Unfortunately, it looks as if the interview was done through email, with a set of questions and answers, and that's fairly disappointing, in the end. It's not bad, don't get me wrong, it's just fairly amateur. However, there's an essay, which was originally a speech, and that makes up for the interview, and in addition, reveals a very socially conscious and strongly left leaning Marxist author. On the link above, the essay is credited as a politically uncorrect look at multiculturalism, but I'd argue it wasn't about multiculturalism at all, but rather about the change in politics and culture throughout the world, and how this is impacting in the worlds that are portrayed in science fiction. At times, I thought the essay suffered from a lack of, admittedly, self confessed research--note: admitting you don't know about a subject does not excuse you from speaking poorly about it--but the general gist of the essay was an interesting one and I had a good time reading it and making little notes in my head and arguing here and there, as is my want.
Anyhow: I kinda dug this little book and the introduction it gave me to an author I'd never heard of before. Might be worth checking out if you're so inclined--the story itself I still have to read, but the blurb was cool, and I'll be doing that when I get the chance.