Should I donate my kidney or part of my liver?

Also, donating will help with persuading people to be more altruistic in general. In psychology you have this concept of a costly signal, which causes people to take your (related) ideas much more seriously.

Are you confident about this?

Donating an organ might seem quite extreme, possibly making the average person view you as 'very weird,' which could have the opposite effect.

Thanks for following up!

I already do work for an animal welfare organization.

Cool!

I looked at the study and it's not about Belgian hospitals, so it doesn't really apply to me.

Even if there is no direct nearterm financial cost, you could plausibly use the time saved by not donating a kidney to generate at least 1 $? For example, I guess the cost to your parents would be higher than this, so they might be happy to donate a few dollars to THL for you not to donate a kidney. Even if not now, the time you save may also increase your income by more than 1 $ in the next few years. For an hourly rate of 20 $/h, it would only need to increase your wages expressed as working time by 3 min (= 1/20*60).

In Belgium you can leave a message to the person you're donating to, so I had planned to leave a message about veganism and effective altruism. I think this will be a very powerful reason to change behavior, seeing as it comes from their altruistic donor.

This sounds inspiring. At the same time, would you feel comfortable donating a kidney if it being good depended on the beneficiary having a sufficiently high chance of becoming vegan or effective altruist? Note the beneficiary would probably rather read a message which does not convey that you are expecting something in return...

If you chose to make a (possibly indirect) request in your message, you may want to consider asking for a donation instead of raising veganism:

• If you trust my numbers on the scale of the suffering of farmed animals, the annual suffering caused by a random human to farmed animals is equivalent to 4.04 DALY (= 4.64*0.870).
• So, for a life expectancy of the kidney recipient of 30 years, the potential gain due to becoming vegan would be 121 DALY (= 30*4.04).
• The above could be averted donating 8.07 $ (= 121/15.0) to THL.
• The kidney recipient would probably prefer to donate a few dozens of dollars to THL over becoming vegan.

As for raising effective altruism in your message:

• I guess the kidney recipient would tend to have an older age than that at which people usually become engaged with effective altruism, so there would be less room to change to a more impactful career, and I assume most of the benefit would come from additional effective donations.
• Giving What We Can estimated each GWWC Pledge leads to 22 k$ of effective donations. If I recall correctly, these effective donations are expressed in terms of ones to GiveWell's top charities, which would mean each GWWC Pledge averts 220 DALY (= 22*10^3*0.01).
• Only around 1 in 1 million people are quite engaged with effective altruism (8 k in 8 billion), and maybe 1 % of the global population knows about it, so only 1 in 10 k (= 10^-6/0.01) people who know about it become quite engaged.
• If the kidney recipient is 100 times as likely to sign the GWWC Pledge as the above, they would have a 1 % (= 100*10^-4) chance of signing it.
• As a result, the expected benefit of your message would be 2.20 DALY (= 220*0.01), which corresponds to 14.7 % (= 2.20/15) of the benefits to the recipient I mentioned in the previous comment.
• So it appears that raising effective altruism in your message does not significantly increase the overall benefits.

My best guess is that I had better not donate a kidney. However, I should note the calculations in this and my past comments involve a great deal of uncertainty. Yet, in my view, the uncertainty also illustrates it is unclear whether donating a kidney is good/bad if one's marginal earnings/savings are going towards the best interventions to help animals.

For what it's worth, I upvoted and disagree-voted, because I think I think you're wrong and because you clearly put thought and effort into your writing, and produced the sort of content I think we should generally have more of, even though I'm annoyed locally that "don't do either" is a much easier comment to write than "here's the analysis you asked for", leading to the only serious comments on the post being people stating your view.

I think DC's point is that the donation one can makes from the proceeds of selling the kidney outweighs the counterfactual direct impact of donating the kidney.

I see. Well, that changes my perspective. Originally, I assumed that you did not give away everything except for what is necessary to live. With the context that you are giving maximally, then donating your liver or kidney can go beyond that so it makes more sense why you are asking the question. I don't think analyzing QALYs is strange generally. 

You are quite the EA! Congrats

I already give everything, except what's required for the bare living necessities, away.

While admirable consider whether this is healthy or sustainable. I think donating less is ok, that’s why Giving what we can suggests 10% as a calibrated point. You can of course donate more, but I would recommend against the implied current situation.

This was meant as a joke (I think OP got this) but on reflection it probably wasn't funny / a good opportunity to try to be funny. I actually agree with your empirical/normative point, and I'll retract the comment so others aren't confused.