What's the best structure for optimal allocation of EA capital?

I find some of the statements in your post a bit jarring, and this is not the first time I feel like this when reading your writing. The founders of Good Ventures are multi-billionaires who have been influenced by EA ideas which stem to some extent from the EA community. This is excellent. But the EA community does not have ownership over this money. Your writing makes it sound like it does, which I find presumptuous and off-putting.

For the future, I would recommend that you should try to better understand the relationships between different individuals and institutions that are associated with the Effective Altruism community before asking questions like this one.

(writing in personal capacity here, not as a mod)

Rough estimate: if ~60% of Open Phil grantmaking decisioning is attributable to Holden, then 47.2% of all EA capital allocation, or $157.4M, was decided by one individual in 2017. 2018 & 2019 will probably have similar proportions.

It seems like EA entered into this regime largely due to historically contingent reasons (Cari & Dustin developing a close relationship with Holden, then outsourcing a lot of their philanthropic decision-making to him & the Open Phil staff).

This estimate seems to have a lot of problems with it, from attributing so much credit to Holden that way not only seeming in practice treating him as too unique an actor without substantiation, if not in principle playing fast and loose with how causation works, while being a wild overestimate from nowhere. This is a pretty jarring turn to what up until that point I had been reading as a reasonable question post.

I think that there's a pretty compelling case for Cari & Dustin to give everything to Open Phil. The main reason is that Open Phil is already evaluating and funding the other options, and will continue to do so. They are funding many moonshots (AI risk), and are basically funding many smaller grants (through things like regranting programs with BERI and CEA).

If they were to give directly to moonshots or other projects, that would just mean moving the decision from Open Phil staff to Cari & Dustin individually, which seems weird to me. They could hire other people to do this, but at that point they are basically making a competitor to Open Phil.

Should they sponsor an Open Phil equivalent/competitor? My guess is that this would most make sense if this other organization were sufficiently different and/or specialized; though in these cases, I'd expect Open Phil would be happy with them and consider funding them directly; they would be less of an equivalent and more of a collaborating group. If they were too similar they would compete for talent; I think much of the best talent is at Open Phil, so this would be a struggle for them.

From what I understand, Holden really doesn't have complete power. If his influence were too high, that could be modified while keeping the main Open Phil relationship the same.

The general structure of "I'm rich, so I'll make one, and only one, group to decide, on a high level, what to do with my money" seems pretty reasonable and common to me.

Separately, I'd of course like to see other mega-billionaires also come in, but that's somewhat of a separate issue.

A less drastic option would be for OpenPhil to just hire more research staff. I think there's some argument for this given that they're apparently struggling to find ways to distribute their money:

1) a new researcher doesn't need to be as valuable as Holden to have positive EV against the counterfactual of the money sitting around waiting for Holden to find somewhere to donate it to in 5 years

2) the more researchers are hired, even (/especially) when they're ones who Holden doesn't agree with, the more they guard against the risk of any blind spots/particular passions etc of Holden's coming to dominate and causing missed opportunities, since ultimately as far as I can tell there aren't really other strong feedback mechanisms on the grants he ends up making than internal peer review.

(I wouldn't argue strongly for this, but I haven't seen a counterpoint to these arguments that I find compelling)

As a typical EA nitpicker, I will avoid answering your substantive question and instead point out that your data may be missing some areas - e.g., independent EA donors (probably a few tens of millions per year) and Founders Pledge / Effective Giving (unknown, but potentially tens to hundreds of millions per year toward EA stuff). Still, I do expect OpenPhil to be a large percentage of EA capital allocation.

Why are you asking this question? I'm asking because it seems more like an academic exercise in what would be a better capital allocation structure if one were to be had, when in practice it doesn't seem like will get there.