Effectiveness of Giving Blood
I believe past discussion about giving blood within EA has undervalues doing so and hopefully the reasoning laid out here will show why.
Some caveats first; I think that some of the reasoning used here may only apply to certain blood groups: i.e. universal donors, additionally past discussion has focused on QALYs and reaches a different conclusion to me - it may be that using different metrics leads to different conclusions or that my method is flawed however due to the limited information about the stats of giving blood and limited discussion within EA (2 posts one against and one for blood donation being effective as far as I can tell) means having a discussion at al could be useful.
My reasoning
- Each whole blood donation produces 1 unit of blood (~about 1 pint although the exact amount is not important for this argument)[1]
- About 1/3 of blood donations are used for emergencies[2]
- I am assuming that in such an emergency the patient would die if they do not receive a blood transfusion
- When used in an emergency 8-10 units of universal donor blood is used initially[3] (I will use the conservative 10 units going forward)
- This means a 1 unit donation makes up 10% of the blood used/needed to save a life
Overall this means we have: 1/3 chance of a donation being used in an emergency * a 1/10 contribution to saving a life in the emergency equating to ~1/30 average life saved per donation.
This does not take into account that the 10 units is for the intial 24 hours of transfusions, after which other blood types can be used. This also does not take into account the other 2/3 times where if not saving a life the donation goes on to improve someone's well-being/health. Additionally the concrete information about blood donation and how it is used is lacking and claims about each donation saving up to 3 lives are inaccurate at best and misleading at worst. Furthermore statements of "1/3 of blood is used for emergencies" may be because 1/3 of blood donated is universal and thus 100% of a universal blood donator's blood may be used in an emergency - greatly improving the impact for them; this seems unlikely but these points hopefully show that the 1/30 estimate is likely to be conservative rather than optimistic.
This would make each donation roughly equivalent to a (1/30*5000) $166 donation to the Against Malaria Foundation for maybe an hour of time.
[1]
[2]
[3]
2024 edit: This is being shared as "you shouldn't donate blood". I think many people should donate blood and it largely depends on your situation, partially for these reasons
Original comment:
Thanks for doing a quantitative estimate, I think it's a very useful exercise and something we should do more often.
I disagree with your main conclusion for two main reasons:
Something that would make me change my mind is an estimate of how many people are dying because of blood shortages. (I would guess close to 0 in rich countries).
As for donating blood in general, I think the costs and benefits are very location specific.
In Italy, you get free blood tests, an extra vacation day, and a nice sandwich, so it's potentially negative cost.
If all need for blood is met regardless of your donation, your counterfactual impact should be 0. Would Shapley values agree? If it gives the same to everyone, it would mean everyone gets 0 impact.
See this other comment
It depends on how you model it. If you model other donors as part of the environment (like e.g. the needle for drawing the blood), everyone gets 0. If you model each donor as an actor they all gettotal impactnumber of actors. Nuno made http://shapleyvalue.com/ to play around with it
Could you say why? Or link somewhere that explains the advantages of counterfactuals? I had never heard of Shapley values, but opened the post and read some and immediately thought "oh my god yes!".
Let's say you had $5k to donate and you could donate it to:
To maximize a naively calculated Shapley value you would choose the first one, even though the second one leads to better outcomes (more lives saved in expected value).
I'm a bit unsure about the general principle and the details, probably there's a way to compute Shapley values that would maximize the expected value in this case as well, but I think it would also apply to the blood donor case.
Very low confidence in this, but I think Shapley values are useful for coordinating strategic agents that act in response to each other, and to avoid double counting, but not when the actions of other agents are not influenced by yours.
This comment on the Shapley values post explains it better
This post might be interesting for some details and proposes some solutions
Thanks. I think I need to dive deeper into the mathematical definition to understand this. It seems to me that counterfactual value is not as well defined.
Short objection: it is not necessarily true that higher expected value = better. For example, in this scenario for low enough risk tolerance the first scenario would be better.