This seems to confuse costs and benefits, I don't understand the analysis. (ETA: the guesstimate makes more sense.)

I'm going to assume that a unit of blood is the amount that a single donor gives in a single session. (ETA: apparently a donation is 0.5 units of red blood cells. The analysis below is correct only if red blood cells are 50% of the value of a donation. I have no idea what the real ratio is. If red blood cells are most of the value, adjust all the values downwards by a factor of 2.)

The cost of donating a unit is perhaps 30 minutes (YMMV), and has nothing to do with 120 pounds. (The cost from having less blood for a while might easily dwarf the time cost, I'm not sure. When I've donated the time cost was significantly below 30 minutes.)

Under the efficient-NHS hypothesis, the value of marginal blood to the healthcare system is 120 pounds. We can convert this to QALYs using the marginal rate of (20,000 pounds / QALY), to get 0.6% of a QALY.

If you value all QALYs equally and think that marginal AMF donations buy them at 130 pounds / QALY, then your value for QALYs should be at most 130 pounds / QALY (otherwise you should just donate more). It should be exactly 130 pounds / QALY if you are an AMF donor (otherwise you should just donate less).

So 0.6% of a QALY should be worth about 0.8 pounds. If it takes 30 minutes to produce a unit of blood which is worth 0.6% of a QALY, then it should be producing value at 1.6 pounds / hour.

If the healthcare system was undervaluing blood by one order of magnitude, this would be 16 pounds / hour. So I think "would have to be undervaluing the effectiveness of blood donations by 2 orders of magnitude" is off by about an order of magnitude.

The reason this seems so inefficient has little to do with EA's quantitative mindset, and everything to do with the utilitarian perspective that all QALYs are equal. The revealed preferences of most EA's imply that they value *their* QALYs much more highly than those of AMF beneficiaries. Conventional morality suggests that people extend some of their concern for themselves to their peers, which probably leads to much higher values for marginal UK QALYs than for AMF beneficiary QALYs.

I think that for most EAs donating blood is still not worthwhile even according to (suitably quantitatively refined) common-sense morality. But for those who value their time at less than 20 pounds / hour and take the numbers in the OP seriously, I think that "common-sense" morality does strongly endorse donating blood. (Obviously this cutoff is based on my other quantitative views, which I'm not going to get into here).

(Note: I would not be surprised if the numbers in the post are wrong in one way or another, so don't really endorse taking any quantitative conclusions literally rather than as a prompt to investigate the issue more closely. That said, if you are able to investigate this question usefully I suspect you should be earning more than 20 pounds / hour.)

I'm very hesitant about EA's giving up on common-sense morality based on naive utilitarian calculations. In the first place, I don't think that most EA's moral reasoning is sufficiently sophisticated to outweigh simple heuristics like "when there are really big gains from trade, take them" (if society is willing to pay 240 pounds / hour for your time, and you value it at 16 pounds per hour, those are pretty big gains from trade). In the second place, even a naive utilitarian should be concerned that the rest of the world will be uncooperative with and unhappy with utilitarians if we are *less* altruistic than normal people in the ways that matter to our communities.

*5 points [-]