A heuristic I've previously encountered being thrown around about whether to donate to the MIRI, or the FHI, is to fund whichever one has more room for more funding, or whichever one is experiencing more of a funding crunch at a given time. As Less Wrong is a hub for an unusually large number of donors to each of these organizations, it might be nice if there was a (semi-)annual discussion on these matters with representatives from the various organizations. How feasible would this be?
I agree that this would be a good idea, and agree with the points below. Some discussion of this took place in this thread last Christmas: http://lesswrong.com/r/discussion/lw/je9/donating_to_miri_vs_fhi_vs_cea_vs_cfar/
On that thread I provided information about FHI's room for more funding (accurate as of start of 2014) plus the rationale for FHI's other, less Xrisk/Future of Humanity-specific projects (externally funded). I'd be happy to do the same at the end of this year, but instead representing CSER's financial situation and room for more funding.
Many people have an incorrect view of the Future of Humanity Institute's funding situation, so this is a brief note to correct that; think of it as a spiritual successor to this post. As John Maxwell puts it, FHI is "one of the three organizations co-sponsoring LW [and] a group within the University of Oxford's philosophy department that tackles important, large-scale problems for humanity like how to go about reducing existential risk." (If you're not familiar with our work, this article is a nice, readable introduction, and our director, Nick Bostrom, wrote Superintelligence.) Though we are a research institute in an ancient and venerable institution, this does not guarantee funding or long-term stability.