[very quick technical-ish thoughts on a necessary condition] I would guess funding retrospectively today is only useful if you think you're going to increase funding in the future. 

The purpose of funding is to enable people to complete projects -- more people are willing to do a project with more funding, and only really rare, super-duper value-aligned people will do a project with very little funding. 

Retrospectively funding people that are already doing the project ignores they've already signaled they're the type that is happy to do the project for low funding. But, like you said, such funding also signals to future researchers on the margin that their expected funding is higher than whatever it is right now. 

So, it's a way for orgs like OpenPhil to smooth researcher consumption over time if they expect they themselves will be getting richer in the future (and thus be able to increase funding for their projects). Retrospective funding should be set at the transfer required in expectation for the marginal researcher who brings in extra value equal to the cost of retrospective funding (MB = MC)? This argument is in expectation and is likely less effective for more risk-averse people -- if OpenPhil has the money now they should probably just increase upfront funding. 

This also relies on other things, like OpenPhil being seen as trustworthy enough to keep up the scheme of retrospective funding, of the signal of retrospective funding being sufficiently public, etc. 

(On the run now, but I see people linked some stuff in the comments i'll check out soon. If all of what I said is common knowledge already, sorry!!)

Lots of funding is implicitly retrospective in the sense that what you've done historically is a big input into whether individuals and groups get funding. Yet, because most funding mixes several factors including past work, anticipated future work, reputation, etc. I think there may be an open opportunity here.

I'd be particularly excited to see funding for projects that have already occurred where it is clear that the success or failure of the past project is all that is being considered. This might encourage more unconventional or initially hard-to-assess projects and would provide a more concrete signal about which projects actually succeeded historically.

I think retrospective funding is a really good norm to encourage, but the benefits only really start accruing once it's relatively widespread. Once it's common knowledge that one may get paid for self-initiated quality work, there's a very wide-but-weak incentive applied across the whole community. The norm-building itself, however, is a stag hunt with upfront costs.

Notice that this incentive affects the poorest of us most, and the people who don't already have jobs in EA. This means that it fulfills a funding niche that isn't already covered neatly by regular jobs and contract-based funding. (I'm especially thinking about those of us without jobs due to disability, but we'd still like to be paid for contributions during our uptime.)

I think the fact that so many EAs have independently arrived at this idea, is strong evidence in favour of there being a real potential for good here.

 • I have previously independently arrived at the idea.

 • Linda Linsefors wrote about it.

 • Ben Kuhn, Paul Christiano and Katja Grace wrote, about, it in the form of impact certificates. 

 • Remmelt Ellen wrote about it and has a patreon page.

 • Dony Christie has one too.

(If anyone know any other EAs with patreons (or similar), I'd like to know!)

I think we are the tip of the iceberg when it comes to who could potentially benefit from it being a universal expectation that if you do good work for the EA community, you can get paid for it.

Additionally, I think a norm for retrospective funding could open up occasional really high-impact giving opportunities for small-scale donors.

Good article, it was interesting to read)