GiveWell's staff are mostly giving their money in this year, rather than saving to give more in the future. One reason cited by a staff member is:
"I am persuaded by the argument that good done in the present probably compounds over time"
This is true. But does it compound faster than the alternative over all timescales?
Paul Christiano has pointed out that while charitable giving such as cash transfers and basic health services probably compound (socially) very quickly to begin with (maybe 20% in the first year), these incredible rates of compounding must decline over time. Otherwise these small charitable acts would quickly become responsible for all of the good in the world. What sustainable level of compounding can they achieve in the long run? The global economic growth rate, which would mean they converge to, at most, a fixed share of the world's economy or welfare.
High-risk business investments by nature compound more quickly than the global economic growth rate. This is the classic 'r > g', which has become widely understood due to Piketty.
As a result, in the long term, investing at this higher rate to fund a much larger donation long in the future could be better.
For the sake of illustration, let's say the global economic growth rate is 3%, the return on business equity is 5%, and the internal rate of compounding of say, cash transfers, is 20% in the first year, 18% in the second, then 16%, 14%, 12%, 10%, 8%, 6%, 4%, and 3% thereafter. (This set of numbers is probably generous to the 'giving later' strategy, but it will help to highlight the difference.) Holding all else constant, how long would the 'invest and give later' strategy take to catch up?
The answer is about 40 years:
What if you also count the same initial burst of rapidly compounding social impact at the point that you give later - say, in year 28?
You get a bigger take-off, because the donation itself is much bigger when given later. Now 'give later' looks significantly better.
I think the natural response is that 'GiveWell classic' donors expect opportunities to end extreme poverty to dry up significantly over such a timescale. It may be that extreme poverty and malaria are eradicated, or nearly so, by that time. By then the world will be richer and the very poor much less numerous, and so the difficulty of finding extraordinary opportunities much higher. This seems entirely plausible.
If the cost effectiveness of the best giving opportunities were to decline by 2% each year - roughly a halving every 40 years - then the 'invest and give later' strategy won't be able to catch up.
Whether the decline is actually that steep, I'm not sure.
And if you're giving to causes other than global poverty, quite different considerations can dominate.
"...these incredible rates of compounding must decline over time. Otherwise these small charitable acts would quickly become responsible for all of the good in the world. What sustainable level of compounding can they achieve in the long run? The global economic growth rate..."
"High-risk business investments by nature compound more quickly than the global economic growth rate. This is the classic 'r > g', which has become widely understood due to Piketty."
Maybe I'm missing something, because I see this pair argued a lot, but when phrased this way this pair of arguments seem to be in tension.
I understand the argument that donations earning even 2% above the global economic growth rate in the very long run would result in a single small donation eventually being responsible for virtually all good done (a seemingly absurd conclusion), but by the exact same token that means a high-risk business investment earning even 2% above the global economic growth rate in the very long run would eventually be making annual returns greater than annual world GDP (an equally absurd conclusion). So in fact both must eventually decay to the world growth rate.
It must be said that Paul, AFAIK, doesn't frame the argument this way. From the post you linked to:
"Here’s the problem: if you give your money well, it might compound much faster than it would have in your bank account—but only for a while. Over time the positive effects will spread out more and more, across a broader and broader group of beneficiaries, until eventually you are just contributing to a representative basket of all human activities. Eventually, my investment will compound at the rate of world economic growth, rather than at the particularly promising interest rate I was able to originally identify."
In other words, with an investment the return keeps coming in to you and you can continue to direct it to activites which are above-average promising (or above-average risky). But with a donation you essentially lose control over it immediately and so you shouldn't expect it to stay in above-average promising territory for very long at all; the timeline on 'eventually' is short. If you could somehow capture a fraction that initial high social return and maintain control of it, e.g. if from that initial 20% return on cash transfers you received 6%, then donating would dominate, but in practice that's very difficult. Microfinance is arguably an attempt to do exactly this, but unfortunately doesn't appear to have the great social returns we're looking for.
Off-topic, but thinking about it in terms of control also highlights why meta-activities might well be in a different category. If you give money to a meta-activity that generates 'EA dollars' at a high enough multiplier on a short enough timeframe, then while you've lost control of your money the control has been passed on to people who you might reasonably expect to also be searching for above-average promising activities.
Hey AGB, I remember thinking of the same point years ago and Robin Hanson explaining to me how it works. Basically it is the case that if someone left all their wealth in business equity to accumulate without any interference, they would slowly converge on owning all the wealth in the world (at least assuming a stable investment environment).
The difference is that social impacts like better health or education are not recaptured by the donor, and instead just diffuse outwards until the gains are spread across a wide range of people and projects. However a ... (read more)