This article was written by Thomas Kelly and Josh Morrison, who asked me to format and post it on the Forum. It makes a detailed case which I'd encourage people to read - it's made me seriously consider donating, since I hadn't realised the health costs were so low. People in the UK interested in donating can do so here; people in the US can do so here.
This piece makes the argument that kidney donation is a reasonable choice for many effective altruists. For some relevant background information, I donated my kidney through the National Kidney Registry in September 2014. I’m also the cofounder of Waitlist Zero, a nonprofit that seeks to end the kidney shortage by promoting support for living kidney donors and increasing living donation rates. This is also going to be more relevant to potential donors within the United States as I understand more about kidney donation in this country.
I encourage EAs who are considering kidney donation to talk with me or my co-founder Josh (also a kidney donor). We definitely understand it’s not a choice for everyone, and we aren’t interested in making a hard sell to become a donor. But we are interested in knowing what motivates people to consider donation, and we also have ideas on how to maximize the (significant) public awareness and political benefits of individual non-directed donations.
Table of Contents
a. Direct Benefits of Kidney Donation
i. Benefits of an Individual Transplant
ii. Kidney Chains
b. Indirect Benefits
i. Is Kidney Donation Contagious?
ii. Political Efficacy of Donor Support Movement
a. Surgical Discomfort, Inconvenience, and Risk of Complication
b. Long-Term Risk
i. No Decrease in Life Expectancy
ii. Increased Risk of Kidney Failure
iii. Minor Long-Term Income Effect
1. Financial Effect of Mortality Risk
2. Financial Effect of ESRD Risk
c. Immediate Financial Costs of Kidney Donation
4. How to Evaluate the Donation Choice as an Effective Altruist
a. How Does Donating Compare to Other EA Choices?
b. Now vs. Later
c. EA Identity and Movement Building
The direct benefits of kidney donation are somewhat difficult to calculate, but our best estimate is an increase of about fourteen quality-adjusted life-years saved with an optimistic estimate of twenty QALYs and a pessimistic one of six. Significantly higher indirect gains may be possible by influencing others to donate and by advocating for policies that would end the transplant shortage, though these gains are more uncertain.
Kidney donation is a significant but laparoscopic and broadly safe surgery with a hospital stay of a couple nights and a return to work within a few weeks. It does not decrease one’s life expectancy and causes long-term harms in less than 1% of cases. If one does not have paid medical leave, the direct financial costs of lost wages may be significant.
For a donor who doesn't forgo wages or pay significant travel expenses, the expected benefits to recipients are more than 100 times the expected costs to the donor (both calculated in QALYs).
The decision to donate is broadly consistent with EA principles. Different EAs will give different weights to the inconvenience, discomfort, and health effects of donation, and comparisons to effectiveness of monetary donations are challenging. That said, depending on subjective valuation of costs, many EAs may find kidney donation’s cost-effectiveness to be of a roughly similar order of magnitude to other EA interventions such as monetary donations to a GiveWell-recommended charity.
Direct Benefits of Kidney Donation
A kidney donor who gives to a stranger can cause multiple transplants. It is difficult to calculate the impact of each transplant, but it is clear they yield a significant number of life-years, with our best estimate as being about 14 quality-adjusted life-years.
Benefits of an Individual Transplant: A commonly used estimate from 2004 is that kidney recipients of a living donor can expect to receive an increase in 3.5 years of quality-adjusted life compared to remaining on dialysis. While there is some definite uncertainty in this figure, our estimate would be something closer to ~8 QALYs/transplant. The difference is due largely to technological improvement, lags in the data, sampling bias, and incongruity with deceased donation results.
Our Estimate: The half-life of a living donor transplant is 14.2 years. Patients are generally medically eligible for transplant when they have a survival prognosis of about 5 years on dialysis. If we were to take the experience of 60-64 year old patients as typical (since their median life expectancy on dialysis is 5.1 years), their average life-years gained per transplant though a transplant would be 8.9 (14.0-5.1). The quality adjustment used in the Matas paper discounts a transplant year of life at 84% and a dialysis year of life at 68%, though we think that estimated difference might be conservative, since dialysis is very burdensome. Using that discount, however, implies a QALY gain of 8.29 years (14.0*0.84-5.1*0.68).
Given the difference between our calculations and the Matas figure, we’ve tried to be conservative in our estimate. Nevertheless, we think there are good reasons for optimism.
1. Technological improvements have occurred in the past decade and are likely to be underrepresented in the data due to time lags in reporting. The Matas and Schnitzler 2004 figure relies on data from patients who were waitlisted or received transplants between 1995 and 1999, when 5.7% of kidneys were reported to fail within a year of transplant. Now 3.2% do. The 14.2-year graft-survival figure is itself incomplete because it refers to kidneys transplanted in the late 1990s, and survival rates have been increasing since then. For example, 2013 figures reported that the percentage of transplants that fail within five years of transplantation fell to 15.4% from 17.5% in the previously reported year.
2. Methodological Questions: The Matas figure only comes from recipients on Medicare, excluding healthier, wealthier recipients with private insurance who likely live longer. Note that the Matas figures also discount QALYs by 5% annually.
3. Kidney Exchange Chains: If you donate to start a chain (see below), your transplant may last longer: 3 year graft survival rates are about 1.5 percentage points higher in chains than in average living donor transplants, which makes sense since chains are able to deliver higher quality matches.
4. Deceased Donor Estimates: It is hard to reconcile estimates of deceased donor impact with QALY estimates as low as 3.5. Living donor kidneys last about 1.5-1.7 times as long as deceased donor kidneys. Estimates of deceased donor impact between 1999 and 2011 have given a range of 2-10 years with an unweighted average across studies of 4.31 years gained.
Kidney Chains: A non-directed kidney donor can usually facilitate more than one patient by facilitating chains of paired kidney exchange (exchanges between incompatible donor-recipient pairs). These chains of donation include a mean of 4.6 transplants, though the longest on record led to thirty-six transplants. That said, it is not correct to think of one non-directed donor as being the but-for cause of every transplant in the chain—an easy-to-match pair in the matching pool will likely become a part of some chain within a few months. Hard-to-match pairs are more difficult to calculate – some patients can only match with less than 1% of the population. Generally, chains alternate between easy-to-match and hard-to-match pairs. Donors with O blood type start significantly longer chains. Roughly guessing, we expect participating in a chain to cause 1.5-2 transplants that would not have otherwise occurred.
Combining our estimates, we'd guess that donating to start a chain leads to ~14 QALYs, though there is substantial uncertainty around the right figure to use with a range of 7-20 seeming realistic.
Is Kidney Donation Contagious? It’s possible that your living donation will persuade others to donate. If I hadn’t read stories about other people donating, I doubt I would have. Other non-directed donors I know have reported people they know personally deciding to donate in part due to hearing their stories.
Non-directed kidney donation has grown substantially over the last few years. However, a sizeable fraction of this increase may be attributed to a coordinated effort to encourage Orthodox Jews to become non-directed donors to other Orthodox Jews.
Kidney Donations to Strangers Per Year in US
In England, since 2009 when their transplant system began allowing non-directed donation and a small non-profit began publicly raising awareness, such donations increased from 0 to 10% of all living donation, compared to 3% in the U.S.
It is obviously difficult to estimate the probability distribution, but for an effective altruist who is reasonably open about their donation (e.g. perhaps talking to friends and colleagues about it privately or writing for a public venue), I think it's fairly likely that you would eventually convince someone else to donate.
Political Efficacy of Donor Support Movement: Non-directed kidney donors have a powerful story and unique moral authority for advocating political change for the transplant system. Policy measures exist that would end the transplant shortage and reduce government healthcare spending by providing support to donors (such as health insurance or an annuity) sufficient to clear the shortage between need and availability. Each year about 20K more people are added to the waitlist than receive a transplant, which means ending the shortage through living donation would save ~160K QALYs/yr. It is difficult to quantify one’s political impact, but for EAs who think this cause is worthwhile, donation should be more compelling.
Surgical Discomfort, Inconvenience, and Risk of Complication: Kidney donation is a laparoscopic surgery that typically necessitates a typical hospital say of two nights, prescription painkiller usage of about 5-8 days, and a return to deskwork within 2-4 weeks. For donors who do not have high blood pressure, the chance of death during surgery is about 1.3/10,000 – about the same as in childbirth. For donors taken as a whole, it's 3.1/10,000. Short-term complications affect about 2-5% of donors and typically involve things like wound infections.
The total QALY costs of this discomfort and risk are not large. The undiscounted QALY cost of a 3.1/10,000 risk to a person with 60 remaining years of perfect-quality life is 0.019 QALYs (roughly equivalent to a week of full value life). I haven't investigated the disability weights that should be applied, but assuming that a donor gets no value from their time in the hospital, half value from the following week, and ¾ value from the following 4 weeks before returning to full health, the total "QALY cost" of the operation, hospital stay, and recovery period is <2 weeks. Combining the risk of death and the hospitalization and recovery period, we get costs of ~0.06 QALYs for donating.
At face value, this may seem surprisingly low – donating a kidney is only as bad as giving up 3 weeks of life? Upon reflection, though, this makes sense – donors are able to return to work and most everyday activities within 4 weeks, and run only a very small risk of death.
Note that the above assumes incurring zero utility from donating, but that’s unlikely. Donors may have many positive experiences (e.g. reading, spending time with friends or family, developing interesting stories) during those 4 weeks and should expect a feeling of pride in the tangible and public accomplishment of donation even above what might be likely from a more abstractly-experienced financial gift.
Most of the costs that prevent people from donating in practice seem to be psychological ones (i.e. fear) rather than these literal incapacitation costs. Of course, these will vary across potential donors, and effective altruists may be particularly well-disposed to take them on.
No credible studies have demonstrated that kidney donation decreases life expectancy. However, it does increase the risk of kidney failure. The best data currently indicates that long-term medical harms affect less than 1% of donors.
No Decrease in Life Expectancy: Kidney donation has not been shown to measurably decrease long-term life expectancy. Donors live longer than the general population because they are healthier to start with. The remaining kidney grows after surgery to accommodate the function of the previous kidney, and chronic kidney disease tends to impact both kidneys equally. A study of World War II soldiers who suffered a traumatic injury that destroyed one kidney found them to have similar health outcomes to two-kidney’d soldier controls.
Increased Risk of Kidney Failure: The average American has a lifetime risk of kidney failure of 3.2%. Kidney donors must have very good kidney function pre-surgery, so their lifetime risk (if they do not donate) is about 0.14%. A 2014 study indicates that people who donate have a 0.9% lifetime chance of developing kidney failure.
The risk of kidney failure mounts over time and the risk of developing ESRD during one’s working years are much lower. At age 50, only 0.28% of living donors had experience kidney failure. As such the expected loss of income due to ESRD is very low. Kidney failure is typically the outcome of decades of degenerative kidney disease (in about half of cases this is caused by obesity and/or diabetes, so about half the risk is controllable by diet and exercise). Donating one’s kidney likely does not increase the chance of that chronic kidney disease; instead, donating reduces one’s total kidney function to about 70% of where it was before. Only donors with excellent kidney function are allowed to donate, so this does not typically have any health impacts. However, for those who develop chronic kidney disease in the future (a small number), donating reduces somewhat the buffer of excess function before chronic kidney disease leads to kidney failure.
There are several challenges to calculating long-term risk of living kidney donation. The first is that ESRD takes so long to develop. Given the medical advances in kidney donation, such as the switch to a laparoscopic procedure, it’s possible that long-term risks of donation have diminished for current donors but have not yet showed up in the data. That said, the long progression of kidney disease may also imply that studies will tend to underestimate the failure effect due to limitations in follow-up duration, and there may be significant uncertainty about health impact (trying to extrapolate to health effects thirty to fifty years in the future is very difficult). Finally, the significant majority of donors give to relatives making it possible that these related donors are actually at greater risk than unrelated donors (and because of transplant center selection criteria, non-directed donors are likely to be healthier to start with than the average donor).
While kidney failure for living donors remains tragic, living donors receive significant priority on the organ waitlist and are thus much more likely to receive a kidney transplant of their own.
Moreover, it seems appropriate to believe technological innovations like artificial organs are likely on a multi-decade timescale, significantly reducing the expected costs of risking ESRD in middle or old age. Based on this consideration (along with fact that living donors receive priority on the waitlist), I'm inclined to significantly discount the potential long-term negative health effects for donors who are young and healthy today.
A 1% risk of developing kidney failure in 30 years has a relatively limited QALY impact even if not discounted for technological improvement. If the average patient develops kidney failure at 65, and the average donor receives a transplant, they should expect to live about 11 years with a disability weight of 0.84, compared to about 15.5 for Americans without ESRD, yielding a total estimated QALY cost of 0.063 or about three weeks. Nearly any positive discount rate would reduce that cost (30 years in the future) substantially.
Minor Long-Term Income Effects: One argument that’s been made is that kidney donation could be on some level self-defeating from an EA standpoint because it reduces your long-term giving by an amount with greater impact than your donation. We disagree strongly with this position, and think the best estimate of long-term income loss is something less than ~$150.
· Financial Effect of Mortality Risk: If you donate $10K per year and have 40 years of remaining working life, the risk of death in surgery would reduce your donations by only an expected $120. Risks to income from potential kidney failure are unlikely because of evolving technology, but even if they occurred, they're likely to become an issue near retirement.
· Financial Effect of ESRD Risk: Long-term income effects of ESRD risk are likely negligible. Here’s a quick back-of-the-envelop calculation to demonstrate. Say there is a 1% risk of kidney failure, and 50% chances each of retirement, technological improvement, ability to receive a transplant, and defection from the EA cause (each conservative estimates). Say that if none of those conditions holds one would lose $250K in charitable donations thirty years from now. This means that the expected loss will be $156.25 (250,000*.01*.5*.5*.5*.5) in 2044, but this figure needs to be discounted to net present value to be compared to a choice today. If you invest a dollar today at 5% annual compounding interest, in thirty years, it would be worth $4.32. Thus, the long-term income loss expected from kidney donation would be equivalent to paying $36.17 (156.25/4.32) today.
Immediate Financial Costs of Kidney Donation
The costs of surgery and of any complications from surgery are covered by the recipient’s insurance (usually Medicare). However, financial costs you incur in donating (such as lost wages if you don’t have paid medical leave) are typically borne by the donor. In the United States, there is no federal law requiring paid leave for organ donors. However, federal employees receive paid leave, as do employees in many states and employees of companies with generous benefits in other states. The cost of donation for donors who do not receive paid leave is of course substantial. The other major cost of donation is travel, which is reimbursed by the National Living Donor Assistance Center for any donor whose recipient makes under 300% of the US poverty line, and is also under 300% of the poverty line. The National Kidney Registry also reimburses all costs for donors who donate to start chains.
There are meaningful costs that are not reimbursed in the United States. Homemakers who donate do not receive any money to pay for childcare, eldercare, or chores they cannot complete. In addition, there is no compensation for the pain or discomfort of the process.
For full-time employees with paid leave, the financial costs of living donation are greatly ameliorated.
How to Evaluate the Donation Choice as an Effective Altruist
The choice to donate a kidney to a stranger clearly has a powerful positive health effect to the recipients that is at least an order of magnitude larger than the cost to the donor. It fits effective altruist principles by being a gift that is significant to the donor and has a measurable and highly positive impact. This does not by any means imply that donating is the right decision for all (or even most) effective altruists since different people will value the costs of having surgery differently.
How Does Donating Compare to Other EA Choices? Donating a kidney is similar in direct impact to, but on the lower end of, other EA choices like giving money to a GiveWell recommended charity. Donating a kidney gets ~14 QALYs at a cost of something on the order of ~0.1 QALYs. If you can give a month of your life to extend someone else's by 14 years, that seems to be a good decision and one where a small sacrifice yields a significant gain for others. Believing that donating will encourage others to do so or that the returns to political advocacy are high could easily double these expected returns.
GiveWell estimates the cost-per life saved for their top charities as ~$3-5K. Assuming a healthy 50 year lifespan for those who are saved, this works out to $60-$100/DALY. GiveWell cautions not to take these cost-estimates literally, due to significant uncertainty around them.
A possible EA critique to kidney donation is to say that, "If donating a kidney will save ~14 QALYs and a developing world DALY only costs ~$100 to save, then donating a kidney is only worth $1,400 in donations." We think there is something true and important in this argument, and we wouldn't encourage someone to donate a kidney if it meant they would forego significant donations to GiveWell's top charities. But we don’t see why that should be the case, since giving a kidney is a complement to and not a replacement for monetary donation.
Put somewhat differently, "donating a kidney is only worth $1,400 in donations" takes our failure to donate the maximum we could and uses it to avoid orthogonal actions that would be extremely net beneficial but don't necessarily quite reach the benefit-cost threshold we've set for our financial donations. This would also imply an incorrect fungibility between moral choices and is a principle that could lead to worse behavior in the long-run (i.e. constantly forgoing positive-utility actions whose gains are not the same as charitable donations with the best expected value).
Donation may also have benefits personal to the donor, indirect to other transplant recipients, and supportive to the EA cause that are not accounted for in its direct QALY figure, and giving through non-financial donation may also be a useful diversification strategy for one’s altruism.
Now vs. Later: If one intends to donate a kidney, donating now is significantly more effective than donating much later. Currently, the transplant shortage is serious, but future policy or technological change could greatly decrease the marginal benefit of kidney donation. That same change could cause a donation today to be a bridge for the recipient into a period with significantly decreased mortality for kidney failure that they would not otherwise have survived to. Opportunity to influence future donors and the political system are likely also higher now than later.
From a risk perspective, donating when young is inferior to donating when old, because younger donors do not have as much information on future health conditions as older donors (i.e. a 50 year-old without chronic kidney disease will almost certainly never develop it, but a 25 year-old still could). For either group, the absolute risk of kidney failure is still small and less than that of the general population. However, we note that donors who are currently young are more likely to benefit from future advances in technology (such as artificial organs) that reduce the expected costs of donation.
EA Identity and Movement Building: One concern that has been expressed is that, since kidney donation is an unusual and serious choice, donation can marginally pull the EA movement away from the mainstream. This concern comes from a model of successful social movements as incremental and moderate.
A different model finds movements do better when they are dramatic, salient, and compelling. Kidney donation is a very admired choice with clear and identifiable beneficiaries. It is a visible choice and attractive narrative that demonstrates significantly stronger commitment than a non-binding pledge to donate money in the future. It also may open opportunities for a broader discussion of EA principles. The more EAs save the lives of identifiable strangers, the more notice the movement gets and the better it looks.
Additionally, much of the EA movement to date— GiveWell, Giving What We Can, and the earning to give discussion at 80,000 Hours—has focused on money as the core resource we have to allocate. We don't disagree that decisions about money are important, but we think that the EA movement will be stronger and more compelling to newcomers if it can offer a broader variety of ways to make the world a better place. Kidney donation should very much be considered as one of those activities.
Kidney donation confers direct benefits to recipients that clearly exceed the cost to the donor by a large factor (more than a hundred, according to our estimate). It is a tangible choice to significantly and publicly affirm one’s commitment as an effective altruist. For many effective altruists, kidney donation is a good choice, and as someone who identifies as an Effective Altruist, I’m glad I donated.
 Thanks to Josh Morrison for helping write this and to Ryan Carey, Howie Lempel, and Alexander Berger for reviewing it. All mistakes are Josh and my own.
 Matas and Schnitzler (AJT). See also The Problem. See generally National Kidney Registry, Living Donors
 2012 OPTN Annual Report, figure 6.7. See 2012 Kidney Data for the exact figure. If you remove from consideration patients who died for reasons unrelated to graft failure, the half-life of a living donor graft that survives past the first year post-surgery is 26.6 years. OPTN Annual Report 2010
 See Schold, AJT.
 2013 USRDS, p. 266. For comparison, the difference in life expectancy between 45-49 year olds on dialysis (8.3 years) and receiving a transplant (22.8 years) is 14.5 years. Id. These figures include living and deceased transplants and are thus likely to undercount the impact of a living donor.
 Dialysis involves several, uncomfortable treatments several times per week and leaves 80% of patients unable to work, whereas transplant patients can live a fairly normal life. It also has a very high rate of complication compared to transplant. “Adjusted rates of all-cause mortality are 6.5–7.9 times greater for dialysis patients than for individuals in the general population. For renal transplant patients, rates approach those of the general population, yet remain 1.0–1.5 times higher.” Id. To use a specific example, “female dialysis patients in their 30s, 40s, and 50s … are expected to live just one-fourth as long as their counterparts without ESRD. Transplant patients fare better, with expected remaining lifetimes 75–80 percent as long as those in the general population.” Id.
 Survival rates are projected forward from mortality rates in early years.
 Matas and Schnitzler (AJT), pg 218.
 See The Problem for a list of these studies.
 NKR Quarterly Report 2014Q3. The NKR is the largest kidney exchange network.
 OPTN Annual Report 2012
 2012 OPTN Annual Data Report
 Id. See also Ibrahim, NEJM and generally Muzaale, JAMA (2014). Note that a 2014 study indicated more serious health risks (Mjoen, 2013). But this piece had serious methodological problems-- for example, the mean age of the control group was 37.6 compared to 46.0 for the donors, and the study did not have BMI data for much of the control group. See Boudville, Kidney International and Kaplan, AJT for some of the limitations with the Mjoen piece.
 Muzaale, JAMA (2014). See Gill, JAMA (2014), Kasiske, AJKD, and Allegretti, AJT for critiques and commentary of the Muzaale piece. Kidney donation also increases the risk of preeclampsia (a disorder of pregnancy characterized by high blood pressure and large amounts of protein in the urine.) by 5-6%. Ibrahim, AJT, 2009. See also Potential Risks for Kidney Donation for a general overview on risk of donation.
 Muzaale, JAMA (2014)
 The 2014 Muzaale study found the risk of related donors developing ESRD within 15 years was 34.1/10,000 as compared to 15.1/10,000 in unrelated donors, but this result was not statistically significant.
 Discussed in Lavine, Science, Fountain, NY Times, and Krassenstein, 3D Printing News. UCSF is also trying to develop an implantable miniaturized dialysis machine. UCSF, 2013 and Kleffman, San Jose Mercury News.
 See, e.g. Bednets; Bednets vs. Deworming vs. Cash Transfers. See also Deworming Update.
In response to Ryan's comments, thank you for your detailed and informative post. The death risk from kidney removal surgery is 3 in 10,000. If the donor does not have high blood pressure, the risk of death drops to 1 in 10,000. Anonymous kidney donors with high blood pressure are not going to be approved. If someone is donating within a family, they are more likely to share the same health issues, mostly because people in a family eat similar foods. Unhealthy food like meat, dairy, sugar, eggs, oil, spark high blood pressure and diabetes, leading to kidney disease. The Standard American Diet (the SAD) is a huge profit maker for the health "care" industry. That's why heart disease causing steak is served to patients after open heart surgery.
Kidney disease costs billions of our tax money each year. A great deal of of money is saved with donor kidneys because kidney dialysis costs a fortune. There's plenty of data on this which is internet accessible. With good policy, high nutrient foods are promoted and subsidized, and the money saved could be reallocated to truly saving those who will suffer and die without the resources.
Only the super healthy pass the organ donation medical committee's thorough and caring scrutiny that combs through the medical record of potential donors before approving them. Those who are approved as anonymous donors are not at risk for kidney disease. Most people who contract kidney disease eat a high fat, salt and sugar diet. Donors need to pass multiple tests including a stress test, renal scan, psychological evaluation, and CAT scan. One of the reasons for the requirement of the CAT scan is to make sure the donor has 2 kidneys.
Because kidney donors are in top health and therefore at low risk for disease, kidney donors actually outlive average Americans. Donors have no food or drink restrictions. The only lifestyle change is that we can no longer take ibuprofen because the tablets damage kidneys.
In my case, the 8 days I took off work were covered by my sick days, so no income was lost. Was the effort worth the saving of four people who would die in the next couple of years without the new kidney? For Ryan, the answer is no. For me, the answer is a resounding yes. Donations to Give Well did not cease. Hundreds of thousands of health care dollars were saved.
My kidney donation experience was captured in this short video I made. https://www.youtube.com/watch?v=XSsI7IkkmPY I will host a Reddit Ask Me Anything at 3pm EST on February 23rd, 2020.
Hello! I anonymously donated my kidney in January of 2020. This kicked off a kidney chain that provided four kidneys for people. Great article. One point that is missed is that by donating to a stranger and not meeting the recipient builds a greater, more caring bond with strangers.
Anyone among us could have my kidney that has served to end the hell of dialysis, a 12 hours a week that has been described as a "living death." This profound caring for strangers has the power to expand the donors' desire to help those we don't know in the human family.
I am aiming to inform those who may be interested with the knowledge about the possibility of anonymous kidney donation. I did not find out until I was 50. The younger the kidney, the better for the recipient. Live donor kidneys work immediately. Deceased donor kidneys can take 4-6 weeks to start working.
Being an anonymous kidney donor was the best decision I have ever made. Relieving suffering & saving lives is our shared human mission. Our 2nd kidney is not needed for our survival. It’s a vestigial organ, like our appendix. This spare kidney has the power to save strangers' lives. For those who are in top health, consider giving a part of yourself so others can live.
My kidney donation started a chain that provided kidneys for four people, achieving the maximum good from a single gift as an effective altruist does. In order to receive a kidney, my recipient’s loved one volunteered to donate a kidney to a stranger. The recipient of that second kidney had someone donate and so on until a total of four people received new kidneys.
I have started a Facebook Page called Kidneys 4 Strangers. I also made a short video about the adventure. https://www.youtube.com/watch?v=XSsI7IkkmPY
Please feel free to be in touch with questions through the FB page.
On the face of it, it seems likely that removing one of your kidneys will decrease your life expectancy somewhat. For patients admitted to hospital, a substantial fraction, something like a quarter, have problems with mild or moderate impaired kidney function. When you donate your kidney, your remaining kidney compensates, but only to the point that it gives you 70% of your original kidney function. So on priors, we should favour the hypothesis that kidney donation increases your change of getting kidney failure.
Then, we take the evidence into account. The evidence, some of which you point out, has identified time after time that kidney donors have comparable risk of renal failure as the general population, despite being screened for diabetes, severe hypertension and kidney failure. This suggests again that donating a kidney increases your risk of kidney failure.
Then, let's look at more studies, mentioned in your footnote 25: Mjoen finds a large mortality risk from kidney donation. Kaplan effectively criticises Mjoen in relation to mortality rates, but concedes that there is likely to be a real effect on renal failure. Kaplan goes on to speculate that this risk of renal failure might arise from hereditary factors (from being related to the donor), rather than from donation itself. Muzaale, which you cite in relation to the claim that 'kidney donation has not been shown to measurably decrease long-term life expectancy.', shows that risk of renal failure is elevated, even for unrelated donors. By comparing related donors, unrelated donors and nondonors, one can see that the decrease in kidney failure is mostly correlated with donation, rather than heredity.
You cite Ibrahim in relation to the same point. To quote the article: "An increased incidence rate of ESRD in donors compared with non-donor controls is now also corroborated in a recently presented abstract on almost 100,000 living kidney donors from the United States.6 In that study, the incidence rate of ESRD was eightfold higher in donors (comparable to the 11-fold increase in the incidence rate in this Norwegian study). Thus, there are now at least two studies describing an approximately tenfold increase in the incidence of ESRD after donation, which is a serious concern."
All of this evidence strongly supports the common sense view that giving up a kidney will mildly increase the risk of end-stage kidney failure.
End-stage renal failure can often cut short a person's lifespan by many years. Beyond being bad from a selfish point of view, this could also decrease your physical capacity to help others. Kidney failure mostly afflicts people in their post-retirement years. However, this is not always the case, nor is it always the case that people cease useful altruistic activities when they retire. The question from an altruistic point of view is how big this opportunity cost has to be to outweigh the benefits of kidney donation.
It depends how many other ways there are of saving lives. By donating one's kidneys, one saves about 15 years of life. How much would it cost to save 15 years of life through a GiveWell donation? Maybe $2k. So if you care about individuals equally regardless of the country that they're from, then this is about how much one should be willing to pay to save a life. Is it reliable to apply GiveWell's estimates here? Maybe not. Are there other opportunities that will have even better impact? Plausibly. So let's use $2k as a target, ableit an approximate one.
How long would it take to create $2k of value? That's generally 1-2 weeks of work. So if kidney donation makes you lose more than 1-2 weeks of life, and those weeks constitute funds that you would donate, or voluntary contributions that you would make, then it's a net negative activity for an effective altruist.
Kidney donation makes you face a 1/4000 chance of death in the operation. If you've 40 years to live, that's 3 days of expected lifespan lost already. When you are admitted to hospital, you will run a substantial risk of having a recovery that is longer than your funded leave from work. So that's another expected week or so gone. Then, if you run a 1% chance of end-stage renal failure, that might rob you a few more weeks of time, although that time isn't taken from the prime of your life.
All things considered, it seems like if you care about people equally, irrespective of the medical condition they're suffering from and the country they're born in, and if you're prepared to donate your time or earnings, then you will actually be causing net harm by performing a random kidney donation.
I'm a bit late to the party, but a couple quick thoughts from a kidney donor who also does earning to give. First, I used paid vacation time to donate my kidney, so the entire discussion about salary trade-off is inapplicable to me (and I assume would be for most high-earning people). Second, I was working again about five days after surgery. I used those five days to read books I had been planning to read but for which I didn't have the time.
Another benefit of kidney donation that needs to be taken into account: My understanding is that most forms of kidney failure affect both of a person's kidneys, meaning whether you have one or two is irrelevant. But because I donated a kidney, if I ever need a kidney, I go to the top of the waiting list. Therefore, I have actually hedged against the risk of (certain types of) kidney failure by donating a kidney.
When you save the life of a kidney recipient in a rich country, you add a lot more to the global economy than when you save someone who would otherwise die of malaria in a poor country, even if the direct QALY impact is similar. There are also larger effects on scientific progress, geopolitics, etc.
In other contexts, e.g. in the Open Philanthropy Project's assessment of cause areas, such non-QALY impacts (and the indirect effects of those over time) are considered to be of substantial importance beyond the direct QALYs.
I worry about selectively including or discounting non-QALY impacts from situation to situation (e.g. claiming a charity is n times better because it trades higher QALY benefits for lower non-QALY benefits, but when pressed agreeing that non-QALY effects are not negligible) in general, and in this specific case.
At least, the calculation should include both QALYs and monetary earnings of recipients.
Yes, although the monetary earnings of recipients could not be rated the same as if they were going to be donated to for example AMF because the value of funds donated to AMF is likely greater from an impartial point of view than if they went into a random individual's pocket.
There is still low-hanging fruit in bringing gifted children online. A small percentage of kids in developing nations are potential high achievers, autodidacts and could be given access to all the world's knowledge at reasonable costs.
If you think malaria nets aren't leveraged enough to beat kidney donations, other interventions might be.
Legalizing voluntary organ markets could be most effective, since it would both make the poor richer and solve the kidney shortage. But perhaps politics is too hard to change.
I think this argument is wrong for broadly the reasons that pappubahry lays out below. In particular, I think it's a mistake to deploy arguments of the form, "the benefit from this altruistic activity that I'm considering are lower than the proportional benefits from donations I'm not currently making, therefore I should not do this activity."
Ryan does it when he says:
The problem with these comparisons is that they're totally made up. There's a potential one-off activity (donating a kidney) which, Thomas argued above, has large benefits to recipients relative to costs to the giver. There's also a question about how much you donate to charity. Based on the rationales you're giving here, someone who is happy with the cost/benefit tradeoff of donating a kidney as a one off, but is convinced that it's not as good cost/benefit as further donations, should actually increase their donations. However, my impression is that that has not been the reaction to these arguments; instead they justify current behavior/levels of altruism. (Toby, Ryan, correct me if I'm wrong here.) But donating a kidney would, according to most parties to the discussion, be net beneficial on its own terms. So the net impact of these arguments is to prevent people from taking positive sum altruistic actions, thereby reducing value.
There are kinds of costs that do mix between these two activities - genuinely foregone wages. And if your foregone wages were large and you decided that you would offset donations rather that consumption or savings with them, it would be perfectly appropriate to conduct this comparison. (Similarly, if the financial risk to future donations were higher, that would also make sense to offset.) But idly speculating about how much you'd have to be paid to do something, while taking the current level of donation as fixed, results in net negative impacts.
I think it's a problem when the "effective" side of "effective altruism" is used as a argument against the "altruism" side. I should note that Jeff Kaufman and I had this framework argument on his post on this topic a while back on Less Wrong.
"The problem with these comparisons is that they're totally made up." I don't think this is true. I think Toby has been giving >50% of his funds and works on FHI full-time. I've used my savings to implement a career change that I wouldn't pursue for selfish reasons. So I do think we're bottlenecked substantially by our available resources at this point, making the comparison legitimate.
I think that it's good to be a bit softer on people who are partially altruistic though. Dewey has said that effective altruism is what he calls the part of his life where he takes the demandingness of ethics seriously. Jeff Kaufman has written about making a budget for spending on others so one does not go insane about self/other tradeoffs during every visit to the supermarket. Utilitarianism gets roundly criticised for its vulnerability to this objection of 'demandingness' and some people find it quite psychologically challenging to (Jess' recent post here). So I lean toward including people who give only a smaller fraction of themselves to others.
I guess this might be the underlying disagreement. You see this as harmful because it will discourage a beneficial act (even though I don't think it's that beneficial, I admit that this is the part that gives me the most pause), whereas on balance, I think the main issue at stake here is our inclusiveness.
There's a further question of how seriously to take these opportunity cost arguments in general, which I think will be picked up in Katja's thread on vegetarianism.
To follow up on Alexander's point a bit, I think applying the charitable benefits standard to non-charity decisions leads to some really weird results. For example, say someone who identifies as an EA chooses to give 10% of her income each year to a GW charity, and she’s choosing employment between being a schoolteacher for $50K a year or a job that’s not especially prosocial that pays $55K a year; say she has no innate preference between them, prefers to make more money all things being equal, and that being a schoolteacher would be worthmore than the $500 donation.
According to the logic Alexander points to about kidney donation, when deciding whether to forgo the $5000 to choose a socially beneficial job, the right calculus is -- 1. does giving up that money do as much good as donating to a GW charity (i.e. saving a life) and 2. if no, EAs shouldn't do it. That leads to the really weird result, though, of committing EA ideology to rejecting socially positive choices even if they involve fairly small sacrifices (here $5,000).
Let me give one final thought experiment on this point, which can be a variant of the child-drowning-in-the-puddle -- let's say instead of a child drowning, it's an older woman, and you're wearing expensive clothing that'll be ruined. If the EA standard is -- don't do altruistic acts that aren't of similar value to GW charitable donations -- that principle could very well commit you to not saving the older woman, which, again, seems bizarre.
To be clear, that's not to say that should mean donating a kidney -- far from it. Instead considering kidney donation is a way of broadening the options available to EAs beyond giving money.
I'm inclined to agree with Ryan's argument here. One way I look at it is that I wouldn't donate a kidney in order to get $2,000 (whether that was to be spent on myself or donated to effective charities), or equivalently, that I am prepared to pay $2,000 to keep my second kidney. This means that, for me at least, donating is dominated by extra donations.
I am surprised that this comes out as close as it does though. If we didn't have quite so effective charities, kidney donation would be a great option.
Yes, so long as you decide your actions in a purely impartial manner. If some self-interest is mixed in, then kidney donation doesn't look so good anymore.
$2K in a couple of weeks is only the case for very high-earning people. With a more typical income, donating a kidney is probably worth the lost income.
It seems like by donating, you expect to lose a few weeks of life and a few weeks of work (which may or may not be paid, depending on your situation). I'm not sure I correctly remember the QALY/"life saved" ratio, but what I remember is 35 QALYs/saved life, which seems reasonable. If you're making $55,000 and donating 10% of your income, it would take a little less than two months of lost income to make that much. It seems like you're still ahead with the kidney donation at that rate.
Your calculation with the $55,000 dollars assumes that if you work for a week you're only donating 10% of the marginal income that you get, but if you give up that time to kidney donation you're giving 100% of the marginal time cost to charity. That's an unfair comparison.
In an apples-to-apples comparison where a person earning $55,000 gives up 100% of their pre-tax income for the marginal time, it would only take 2 weeks for them to make $2,000.
But it might be a relevant comparison for many people. i.e., I expect that there are people who would be willing to forego some income to donate a kidney (and they may not need to do this, depending on the availability of paid medical leave), but who wouldn't donate all of that income if they kept both kidneys.
I think Ben's criticism is fair, in that a perfectly rational altruist wouldn't make it. That is, if you are willing to give up three weeks of income to donate a kidney, you should be willing to work for three weeks and donate all of your income, not just whatever percentage you donate normally. This is not to say that it's an unreasonable decision in all cases-- taking three weeks off of work to donate a kidney has all sorts of other consequences (you probably get to do a lot of reading while you're stuck in bed), but from a first order altruistic standpoint, at the income level I mentioned it still wouldn't make sense.
Yes, I agree with that, and it's worth someone making that point. But I think in general it is too common a theme in EA discussion to compare some possible altruistic endeavour (here kidney donation) to perfectly optimal behaviour, and then criticise the endeavour as being sub-optimal -- Ryan even words it as "causing net harm"!
In reality we're all sub-optimal, each in our own many ways. If pointing out that kidney donation is sub-optimal (assuming all the arguments really do hold!) nudges some possible kidney donors to actually donate more of their income, then great. But I still think that there are people who would consider donating a kidney but who wouldn't donate an extra half-month's salary instead.
$2K in 2 weeks is $52K / year. For reference, this is less than US GDP per capita. Admittedly it's above the median (it's about the median household income in the US), but still not that far.
Comparing to the fraction of income you donate seems wrong when accounting for lost work, you want to compare to donating all of the foregone income (since other expenses don't generally stop while you miss work).
This can't be the right comparison to make if the 1-2 weeks of life is lost decades from now. The (foregone) altruistic opportunities in 2060 are likely to cost much more than $2000 per 15 DALY's averted.
I think the basic shape of your argument still holds, based on foregone income that you could donate today, but a slightly shorter retirement doesn't look like it makes much difference to one's total altruism (especially if you leave donations to charity in your will).
I had a much shorter facebook status on this a while back:
"Donating a live kidney extends an average of three developed-country lives by, I will guess, an average of 30 healthy years. It will require you to take two weeks off work and accept a 1/1000 chance of death in the operation. The long-term health impacts are negligible.
For my own case, if I were earning to give, I would earn something like $2,000 from an additional week of work. I could expect to earn something like $8m from the rest of my career, 1/1000th of which is $8,000. So I'm giving up something like $12,000 in expected earnings for 90 years of healthy adult life. Assuming that the Against Malaria Foundation can save infants in the developing world for $2,500, I would have to regard a year of healthy life in the developed world as roughly 2.5x more valuable for the kidney donation to be better than just continuing to work and giving the money to AMF.
If I would dislike the two-week kidney donation process more than doing my job and not spending any of the income on myself, then that number will rise somewhat.
I think it's plausible to regard a year in Britain as 3x more enjoyable than a life of poverty in e.g. rural India, though I am far from sure."
The resulting comments were interesting too.
Just a heads-up, many people aren't eligible to become kidney donors. Here are some common disqualifiers (at least in the US):
Criteria vary by transplant center, so if you're interested it's probably worth checking even if you match one of the things I listed. But don't get your hopes up too high.
Here are some of the criteria for one US transplant center.
I agree that diversification would be good for the movement, and I'm excited to see a compelling suggestion of something EAs can do besides donate money. Thanks!
I think that there are potential EAs out there for whom the earning to give model is very costly or unrealistic (people who would have to develop unrelated new skillsets and/or move to new cities). For example, a schoolteacher is probably in a poor position to earn to give (although they can certainly donate money), but they could donate a kidney over their long summer break with no lost earnings.
I think that it's great that some people have decided to give up an organ to help others. If more people did this, it would have a net benefit to the world. Nevertheless, I wouldn't want the public to associate effective altruism with something as radical as this. It would give people an excuse to dismiss EA altogether because they'd see it as only for extremists. To be clear, I'm not arguing against donating organs, just that we need to be mindful that all that matters is the total good being done. Publicizing an extreme act of altruism that could turn many people off of easier forms of effective altruism is not an acceptable trade-off to me.
Austen, I see your point but think you have the wrong model of how social movements work. Basically any successful social movement I can think of (e.g. civil rights, women's rights, gay rights) has had extremists who were important to the movement and has included acts of extremism that were historically important to the movement's self-identity. More to the point, it's impossible to know ahead of time what acts will end up considered extremist, so it's silly to criticize an action that aligns with the movement's values as being against the movement because of potential PR consequences, particularly when the act is non-violent and widely considered admirable. (Another way of saying all this is that effective movements are internally diverse and should be wary of self-policing).
I think you are confusing radicalism of getting attention with that of the form the social change will take. For example, Emily Davison ran onto a race track as a PR stunt, but all she was seeking was voting rights for women, not the right for them to walk around naked. Nelson Mandela was jailed for economic terrorism to bring attention to his cause, but he simply wanted blacks to enjoy the freedoms whites had – nothing radical about that. PETA does crazy publicity stunts sometimes, and perhaps they've had a net benefit, but they do them to bring attention to the abuse of animals on farms, mostly, not to emancipate domesticated dogs and cats. We should make a distinction between extremism in publicity measures with that of the demands that activists are making on society.
To look at EA, the demands it makes on people should also be reasonable: give according to impact, not feelings; be irreplaceable, especially for the more important causes, etc. Making unreasonably large demands on people could result in people rejecting even the easier actions. For instance, studies demonstrate that to promote veganism, it's actually more effective to promote vegetarianism, and let the vegetarians eventually gravitate towards veganism, than it is to directly promote veganism, which results in people not even giving up meat, because avoiding animal products completely is so demanding to people that they end up rejecting the whole veg thing altogether.
Please don't take my comments as policing, I like your post and I think donating kidneys is great, I just wouldn't want to see a CNN segment on EA discussing kidney donation as viewers may use it as an excuse to reject EA altogether.
I think your Qaly estimate is too optimistic. Your survival data of 14 years comes from patients aged 45-49 on dialysis. This group will be relevantly and significantly different to the projected recipients aged 60-65. This group will have different causes for their ESRD, and type 2 diabetes will be a much bigger cause. I would expect this group to have much more mult-system morbidity, and their expected all cause mortality would therefore be higher. (As would immunosuppressive treatment related morbidity).
Re improved survival with living donors, is there enough data to support that for unrelated donors? I would expect improved immunological match from related donors would be an important confounder.
Bernadette, maybe I'm misunderstanding your point, but the 14 year estimate is for patients 60-64 who receive a transplant (this might be a bit unclear as we wrote it though). Patients 60-64 on dialysis can expect 5.1 years of life, so that gives a 8.9 differential, which when you discount years by disability comes to 8.29 or about 8, which is our (admittedly imprecise) estimate. We don't think it's skewed in an optimistic direction though. To be clear, the 14-year overall estimate is 8 per transplant * 1.75 per marginal transplants created by starting a chain.
Patients 45-49 with a transplant have an average life expectancy of 22.8 years (8.3 if they're on dialysis). But we're not assuming they're the median recipient.
I haven't seen half-life outcomes broken out by living related vs. unrelated donors, but 5-year graft survival is similar. See p. 14 of the 2012 OPTN Report -- (http://srtr.transplant.hrsa.gov/annual_reports/2012/pdf/01_kidney_13.pdf). This makes sense because deceased donor organs are not worse primarily because of mismatching but because (besides the fact that they're dead) the quality of donor pre-death is worse (they don't go through rigorous screening; little health data is available; something caused them to die, etc.).
Here's how you present the calculation
I think that's implausible for the reasons above.
Got it! Thanks for explaining that, and I do think we wrote it in a confusing way (sorry!). There are two separate facts --1. the half-life for all living donor grafts is 14.2 years (figure 6.7 here http://srtr.transplant.hrsa.gov/annual_reports/2012/pdf/01_kidney_13.pdf). 2. Expected lifespan for those who receive any kidney transplant between the years of 60 and 64 in particular is 14.0 years. (See p. 266 here -- http://www.usrds.org/2013/pdf/v2_ch5_13.pdf).
Expected lifespan can vary from graft survival half-life both because half-lives are different from averages and (moreso) because most patients end up surviving graft failure and going back on dialysis or getting another transplant (thus extending life further).
We used the 60-64 age as the baseline for the calculation because (1) it's fairly typical of when patients develop ESRD; (2) the life-spans from both dialysis and transplant treatments fit the average transplant candidate; and (3) the transplant survival figure included both living and deceased, so it skewed conservative compared to a figure that only included living, which gave us a margin of error to avoid bias towards overoptimism.
Just thought forum visitors might find it interesting that the new Dumb and Dumber movie is about voluntary kidney donation. Might be an interesting watch if it's something you've thought about :^)
Not a bad movie either: not the funniest but the plot gets pretty exciting.
The claim that kidney donation does not affect donor survival is based mainly on [Ibrahim NEJM 2009], which has a very serious flaw. In that study donors are matched to controls from the general population, which is significantly less healthy than screened donors. In contrast [Mjoen 2013] found very significant reduction in survival rates for donors. A footnote on this EA page claims that [Mjoen 2013] also makes an error in matching to controls with the control group being younger, but the [Mjoen 2013] authors address this concern here:
To summarize, "Drs. Kaplan and Ilahe argue that the difference in mortality between the living kidney donors and controls in our study was due to differences in age between the two groups. There seems to be a misunderstanding about the statistical methods used. They refer to differences in age at baseline, that is, before any adjustment or matching was performed." Refer to the link for more detail.
At this point I would say that the evidence strongly favors the proposition that kidney donation significantly negatively affects donor survivial.
The claim about donor survival is more based off of Segev, 2010, which does use controls matched on health (http://jama.jamanetwork.com/article.aspx?articleid=185508&resultclick=1). (There was an editing error in the footnote above, sorry about that).
Good point about the age-matching, which I'll update our website to reflect. Agree that the Mjoen piece definitely has value (which is why we included it), but there are other reasonable criticisms (like the controls all being drawn from the same region and from an earlier time period) raised as well.
Thanks for your reply.
The JAMA article you cite is not a good one for this discussion, I think, because the median followup was just 6.3 years. The mortality curves for donors and properly matched controls don't start moving apart until about 10 years. At 15 years, the difference is quite pronounced. At 20 years post donation, donors are looking at 50% increased mortality compared to properly matched controls.
Kidney donation is still a huge benefit for recipients, and may be a net benefit, but it is a much bigger risk (I believe) for donors than has been portrayed. Yet major donor web sites (Stanford, Maryland Medical Center) haven't caught up to the research.
Instead of asking for self-sacrifice, why not allow poor people to sell their kidneys? There should be enough willing donors if compensation is high enough. Especially the affluent recipients should be able to leverage their wealth this way. In return, the global poor would have another income option.
Is this banned? If yes, then that means the current kidney shortage is a form of artificial scarcity.
Politically, it probably wouldn't be feasible to allow organ sales, but there are a lot of intermediate policy alternatives likely sufficient to end the shortage by supporting donors better (just to start, you could pay lost wages and travel, but you could also provide health insurance, tax credits, or an annuity to donors). If you think that's a good idea (we think it would save about 160K QALYs annually), donating your kidney gives you unique moral authority and power in advocating that policy.
Also you might be interested in signing this open letter if you support benefit for donors --http://www.ustransplantopenletter.org/home.html
But it's a kind of moral authority that might disappear when you look at it too closely right? If the reason you're donating is to get the moral authority, then it's not clear that it's a virtuous act anymore!
Another policy change is opt-out for (after-death) organ donation rather than opt-in. How do you feel about the likely effectiveness of that?
In terms of opt-out, I only know the data in the U.S. but basically while it might be a good idea, it's unlikely to yield significant increases: it seems like such an attractive decision architecture/nudge type intervention, but when you dig in, it's a much closer call (which is why Sunstein and Thaler don't recommend it, for example).
The current American system is more of a hybrid than clear opt-in. Right now, about 75% of those who could become deceased donors ultimately consent to do so (about 40-50% are registered as organ donors and of the remainder, the family consents about 40-50% of the time). Thus even if an opt-out system worked as intended, the marginal upside isn't so high (and the downside to it failing or being counterproductive would be quite severe). Spain, the country with the highest deceased donation rates in the world, ostensibly has an opt-out system, but the families are very empowered to say no to donation, and the actual difference between Spain and the U.S. is that in Spain a lot of their deceased donors are over 70 and here very few are.
There'd also be some risks of going to an opt-out system. So imagine what happens when someone is actually eligible to become a deceased donor -- they're brain dead, so their death is often sudden and unexpected to their family. Let's say the donor didn't choose to opt out. What do you tell the family who's in the room with a brain-dead patient whose heart is still beating -- "she's dead. Now you have to leave the room so we can harvest her organs"? If they have no control over what happens to their loved ones body, you can imagine a lot of people becoming pretty upset, even people who might have been persuaded to say yes to donation. The deceased organ donation relies on the public's support and good graces, so if you have repeated instances of grieving families publicly decrying the opt-out system, that creates a significant risk that the change will be counterproductive.
I haven't studied organ donation, but I was under the impression that the current state of the (admittedly non-experimental) evidence suggested that switching to opt-out would likely yield significant (though not huge) increases in organ donation, e.g. see here and here.
Is it easy for you to explain, or link me to, the reasons for your skepticism?
The U.S. is third in the world for deceased donation per million persons. The difference between us and the #1 (Spain, which has a suite of good deceased donation policies, one of which is a version of presumed consent) can be explained by our generally not accepting deceased donors over 70 and Spain doing so. http://onlinelibrary.wiley.com/doi/10.1002/lt.23684/full
Also, the kidney shortfall is 20K/yr. Total deceased donor kidneys are about 12K per year. Opinions differ as to what percent of those eligible to be deceased donors donate, but the official government estimate is 75% (I think a range of 50-75% is probably credible), so even if all eligible deceased donors donated, there would still be an enormous shortfall in kidney transplants each year.
(re: political credibility) -- Ehhh, let's say you become a doctor because you think healthcare is important. You want to help people and by being a doctor, you hope to have the status to advocate politically for expanding access to healthcare. I don't see how your authority is impugned because of your desire for advocacy. I think what you're going for is the loss of authority if you have an ulterior motive that cuts against the stated motive -- e.g. if you join a church for political gain but don't believe in god. As a kidney donor, though, your desire to give and desire to change policy are aligned.
I believe this is banned in many countries, including the US. I chatted to Alexander Berger of GiveWell (who's donated a kidney) about it once, and if I recall the conversation correctly he said he thought it should be legal.
Yes, kidney selling is officially banned in nearly every country. My preference, at least in the U.S. context, would be to have the government offer benefits to donors to ensure high quality and fair allocation: http://www.nytimes.com/2011/12/06/opinion/why-selling-kidneys-should-be-legal.html
This is an interesting idea, I don't think it is likely to be something I take up in the near future because I think there are many other things that have priority and this would take a good amount of time to study and get the confidence that it was a good thing in detail. However, it is the kind of interesting idea to add to a bucket list when I have time to study in more detail - thanks for bringing it to our attention.
I would be interested to hear whether readers do or don't consider doing this.