It's a concept thrown around a lot in EA circles, but I was surprised that I couldn't find any papers fleshing the idea out. The most cited link is a blog post from 2009: http://www.overcomingbias.com/2009/01/moral-uncertainty-towards-a-solution.html
I also found these two resources:
http://users.ox.ac.uk/~mert2255/talks/parliamentary-model.pdf
Is there any better exploration of the concept out there?
Nice! Seems like a cool paper. One thing that confuses me, though, is why the authors think that their theory's "moral risk aversion with respect to empirically expected utility" is undesirable. People just have weird intuitions about expected utility all the time, and don't reason about it well in general. See, for instance, how people prefer (even when moral uncertainty isn't involved) to donate to many charities rather than donating only to the one highest expected utility charity. It seems reasonable to call that preference misguided, so why can't we just call the intuitive objection to "moral risk aversion with respect to empirically expected utility" misguided?