Thanks for the pointer! For those too lazy to click on it, Nick Bostrom comments in that thread:

Much of the dispersion is caused by the lack of unrestricted funds (and lack of future funding guarantees). Since we don't have enough funding from private philanthropists, we have to chase academic funding pots, and that then forces us to do some work that is less relevant to the important problems we would rather be working on. It would be unfortunate if potential private funders then looked at the fact that we've done some less-relevant work as a reason not to give.

and

A high fraction. "A dollar's worth of research" is not a well-defined quantity - that is, the worth of the research produced by a dollar varies a lot depending on whom the dollar is given to. I like to think FHI is good at converting dollars into research. The kind of research I'd prefer to do with unrestricted funds at the moment probably coincides pretty well with what a person with SIAI-typical estimates would prefer, though what can be researched also depends on the capabilities and interests of the research staff one can recruit. (There are various tradeoffs here - e.g. a weaker researcher who has a long record of working in this area or taking a chance with a slighly stronger researcher and risk that she will do irrelevant work? headhunting somebody who is already actively contributing to the area or attempt to involve a new mind who would otherwise not have contributed? etc.)

There are also indirect effects, which might lead to the fraction being larger than one - for example, if discussions, conferences, and various kinds of influence encourage external researchers to enter the field. FHI does some of that, as does the SIAI.

There are also several informative comments from Carl Shulman, who mentions a cost of about $200k per 2 year postdoc, and estimates FHI getting something like 1 Sandberg or Ord equivalent per 2-3 hires.