Life Extension versus Replacement

Here's his 2008 paper, "Life Extension versus Replacement," which explores an amendment to utilitarianism that would allow us to prefer Life Extension

I feel like the thing that should allow us to prefer life extension is the thing that makes people search for amendments to utilitarianism that would allow us to prefer life extension.

I'm not comfortable spending my time and mental resources on these utilitarian puzzles until I am shown a method (or even a good reason to believe there is such a method) for interpersonal utility comparison. If such a method has already been discussed on Less Wrong, I would appreciate a link to it. Otherwise, why engage in metaphysical speculation of this kind?

A currently living person doesn't want to die, but a potentially living person doesn't yet want to live, so there's an asymmetry between the two scenarios.

I am an average utilitarian with one modification: Once a person exists, they are always counted in the number of people I average over, even if they're dead. For instance, a world where 10 people are born and each gets 50 utility has 10X50/10=50 utility. A world where 20 people are born, then 10 of them die and the rest get 50 utility each has (10X50+10X0)/20=25 utility. AFAICT, this method has several advantages:

1. It avoids the repugnant conclusion.
2. It avoids the usual argument against average utilitarianism, namely that it advocates killing off people experiencing low (positive) utility.
3. It favors life extension over replacement, which fits both my intuitions and my interests. It also captures the badness of death in general.
4. A society that subscribed to it would revive cryopreserved people.

This actually reminds me of a movie trailer I saw the other day, for a movie called In Time. (Note: I am not at all endorsing it or saying you should see it. Apparently, it sucks! lol)

General premise of the sci-fi world- People live normally until 25. Then you stop aging and get a glowy little clock on your arm, that counts down how much time you have left to live. "Time" is pretty much their version of money. You work for time. You trade time for goods, etc. Rich people live forever; Poor people die very young. (pretty much imagine if over-drafting your bank account once means that you die)

Anyway, when I saw this preview, being the geek I am, I thought: "That doesn't make sense!"

The reason it doesn't make sense has to do with the extension v. replacement argument. Until the age of at least 16, and more generally 22-ish, people are a drain rather than benefit to society. The economic cost of maintaining a child is not equal to the output of a child. (I'm obviously not talking about love, and fulfillment of the parents, etc.).

This society's idea is that people of working age would be required to provide the economic cost for their life. However what would actually end up happening is that the birth rates would climb sky high (since people die young, and you need some of your children to make it so that once you can't keep working anymore they can provide hours for you). So society would be burdened with raising and educating a disproportionately large amount of children, but not getting full utility out of them. (aka they would start killing them off once they actually reached working/productive age)

In other words, society pays a lot to raise a kid, and then kills it after only getting a couple of productive years out of it. Does not compute.

So my thought, upon seeing this trailer, was that it would make no sense for that society to allow everyone to have children, and only rich people to live forever. It would make way more sense for that society to allow everyone to live forever, and only allow rich people (who could completely pay for their children's upbringing) to have children. (I am not saying this is at all a "good" idea, but given the premise of the film, it was the much more reasonable alternative).

In other words, you can continue getting utility out of one person if they live forever, but if you are going the "replacement" route you constantly have to be pouring money into their education and upbringing.

Note: I am not actually arguing for extension over replacement in any society other than the rather far-fetched one presented in the movie.

response a) My life gets better with each year I live. I learn new things and make new friends. 2 people who live 12 years will not have the same amount of happiness as I will on my birthday, when I turn 24. I see no reason why the same should not hold for even longer lifespans.

Response b) I privilege people that already exist over people who do not exist. A person living 800 years is more valuable to me EVEN if you say the same amount of happiness happens in both cases. I care about existing people being happy, and about not creating sad people, but I don't particularly care about creating new happy entities unless it's necessary for the perpetuation of humanity, which is something I value.

response c) The personal response, I value my own happiness significantly higher than that of other people. 1 year of my own life is worth more to me than 1 year of someone else's life. If my decision was between creating 10 people as happy as I am or making myself 10 times happier, I will make myself 10 times happier.

Finally, you don't seem to realize what is meant by caring about average utility. In your scenario, the TOTAL years lived remains the same in both cases, but the AVERAGE utility goes far down in the second case. 80 years per person is a lot less than 800 years per person.

First thought: I accept the repugnant conclusion because I am a hard utilitarian. I also take the deals in the lifespan dilemma because my intuition that the epsilon chances of survival "wouldn't be worth it" are due to scope insensitivity.

Second: I attach much more disutility to death than utility to birth for two reasons, one good and bad. The bad reason is that I selfishly do not want to die. The good reason, which I have not seen mentioned, is that the past is not likely to repeat itself. Memories of the past have utility in themselves! History is just lines on paper, sometimes with videos, sometimes not, but it doesn't compare to actual experience! Experience and memory matter. Discounting them is an error in utilitarian reasoning.

I'm perfectly prepared to bite this bullet. Extending the life of an existing person a hundred years and creating a new person who will live for a hundred years are both good deeds, they create approximately equal amounts of utility and I believe we should try to do both.

I already exist. I prefer to adopt a ruleset that will favor me continuing to existing. Adopting a theory that does not put disutility on me being replaced with a different human would be very disingenuous of me. Advocating the creation of an authority that does not put disutility on me being replaced with a different human would also be disingenuous.

For spreading your moral theory, you need the support of people who live, not people who may live. Thus, your moral theory must favor their interests.

[edit] Is this metautilitarianism?

In the replicating scenario, people die twice as much. Since expectations of near death are unpleasant and death itself is unpleasant for the relatives and friends, doubling the number of deaths induces additional disutility, ceteris paribus.

I don't see how this is a paradox at all.

Scenario (1) creates 100 years of utility, minus the death of one person. Scenario (2) creates 100 years of utility, plus the birth of one person, minus the death of two people. We can set them equal to each other and solve for the variables, you should prefer scenario (1) to scenario (2) iff the negative utility caused by a death is greater than the utility caused by a birth. Imagine that a child was born, and then immediately died ten minutes later. Is this a net positive or negative utility? I vote negative and I think most people agree; death outweighs birth.

(As an interesting sidenote, if we lived in a world where the value of Birth outweighed the value of Death, I think most of us would happily change our preference ordering. Eg, If we lived in the Children of Men world, we'd go with scenario (2) because a new birth is more important than a new death. Or if we lived in a universe where there really was a heaven, we'd go with scenario (2) as well because the value of death would be near zero.)

Things get less simple when we take into account the fact that all years and deaths don't generate equal (dis)utility. The disutility caused by Death(newborn) != Death(10 year old) != Death (20 year old) != Death (80 year old) != Death (200 year old). Similarly, the utility generated by a child's 3rd->4th year is nowhere near equivalent to the utility of someone's 18th->19th year. I would assume the external utility generated by someone 101st->200th year to far, far outweigh the external utility generated by the 1st->100th year (contributing to the world by being a valuable source of wisdom). By any reasonable calculations it seems that net utility in scenario (1) significantly outweighs the net utility of scenario (2).

Different people might have different expected values for the utility and disutility of years/deaths, and thus get differing results. But it seems if you had sufficiently accurate data with which to calculate expected utility, you could actually determine what those utilities are and they wouldn't come out equal. However, just because something is incredibly hard to calculate doesn't mean you throw your hands up and say that they must be equal. You do what you always do with insufficient information: approximate as best you can, double check your numbers, and hope you don't miss anything.

I prefer 1 to 2 because I'm currently alive, and so 1 has a more direct benefit for me than 2. I don't know if I have any stronger reasons; I don't think I need any, though.

I really need to fix my blog archive, but I discussed this in the post at the top of this page.

I think it comes down to how you value relationships. I don't want my family replaced, so replacing one of them with someone in a similarly valuable mental state might be equal in terms of their mental state, but because you've broken a relationship I value, the total utility has dropped. Other than this, I'm not sure I can see a relevant difference between extension and replacement.

I assume everyone is familiar with the following argument:

Premise: You are not indifferent about the utility of people who will come to exist, if they definitely will exist. Conclusion: You can't be in general indifferent between people existing and not existing.

World A: Person has 10 utility World B: Person does not exist World C: Person has 20 utility

By hypothesis, you're not indifferent between A and C. Hence by transitivity, you're not indifferent between both A,B and B,C.

Ignoring the fact that replacement tend to be expensive, I'd consider them equal utility if I believed in personal identity. I don't, so not only are the equally good, they are, for all intents and purposes, the same choice.

I guess that my own response to the repugnant conclusion tends to be along the lines that mere duplication does not add value, and the more people there are, the closer the inevitable redundancy will bring you to essentially adding duplicates of people you already have. At least as things are at present, giving an existing person an extra hundred years seems like it will involve less redundancy than adding yet another person with a hundred year lifespan to the many we already have and are constantly adding.

We can deal with this with a thought experiment that engages our intuitions more clearly, since it doesn't involve futuristic technology: Is it okay to kill a fifteen year old person who is destined to live a good life if doing so will allow you to replace them with someone who will live a life that is as good, or better, as the fifteen year old's remaining years would have been? What if the fifteen year old in question is disabled, so their life is a little more difficult, but still worth living, while their replacement would be an able person? Would it be okay then?

The answers are obvious. No and no. Once someone exists keeping them alive and happy is much more important than creating new people. It isn't infinitely more important, it would be wrong to sterilize the entire human race to prevent one existing person from getting a dust speck in their eye. But it is much, much, much more important.

Life extension isn't just better than replacement, it is better by far, even if the utility of the person with an extended life is much lower than the utility their replacement would have.

I suspect that the reason for this is that population ethics isn't about maximizing utility. If it was we wouldn't be trying to create more people, we'd be trying to figure out how to kill the human race and replace it with another species whose preferences are easier to satisfy.* I believe that the main reason to create new people because having the human race continue to exist helps fulfill certain ideals, such as Fun Theory and the various complex human values. If you try to do population ethics just by adding the utility of the creatures being created, you're doing it wrong.

Now, once we've created someone we do have a responsibility to make sure they have high utility (you can't unbirth a child). If we know they are going to exist we should definitely take steps to improve their utility even before they come into existence. And if you're trying to decide between creating two people who fulfill our ideals equally well, which one has a higher level of utility is definitely a good tiebreaker. But a person's utility isn't the main reason we create them. If I had a choice between making a human with positive utility, and making a kiloton of orgasmium, all other things being equal I'd pick the human, because the complex values of a human being furthers my moral ideals far better than orgasmium does.

*Anyone who disagrees and believes that creating human beings (or nonhuman creatures with human-like values) is the most efficient way to maximize utility should consider the Friendly AI problem. Imagine that someone has just created an AI programmed to "maximize preference satisfaction." The AI is extremely intelligent and has access to immense resources. All that needs to be done is switch it on. What is your honest, Bayesian probability that, if you switch on the AI, it will not eventually try to exterminate the human race and replace it with creatures who have cheaper, easier to satisfy preferences?

This is a really interesting issue which I suspect will only get more important over time. I largely agree with Xachariah, but I see a greater dependency on personal preference.

Another way of looking at the problem is to consider individual preferences. Imagine a radical sustainable future where everyone gets to choose between an extended life with no children or a normal life with 1 child (or 2 per couple). I'd be really interested in polls on that choice. Personally I'd choose extension over children. I also suspect that polls may reveal a significant gender gap on this issue, but that's just speculation.

I have a suspicion that linear aggregation of individual utilities over all possible people is perhaps not the best global decision process. There probably should be a discount factor where we discount other potential beings in proportion to their dissimilarity to existing people. We should count existing people's preferences somewhat higher than future descendants who in turn we weight higher than distant descendants and other more remote possible people.

As you phrased it, life extension and replacement seem roughly similar to me. I don't feel the need to modify my utilitarianism to strongly prefer life extension. There are some differences, though:

• Perhaps the later life years are less pleasant than the earlier ones? You're less physically able, more cynical, less open to new ideas? Or perhaps the later life years are more pleasant than the earlier ones? You've had the time to get deeply into subjects and achieve mastery, you could have some very strong old friendships, you have a better model of the world.
• People who live longer might be better at solving the worlds problems. Or having more different people might be better.
• I think of the harm of death as being the removal of the potential for future joy combined with the suffering of those who remain, and replacement deals with the former. While death seems to cause pain to those who continue living in all societies, death of "old age" doesn't seem to cause too much suffering to other people.

I would definitely (selfishly) prefer life extension.

(I'm a total utilitarian)

This presumes that extending the life of an existing person by 100 years precludes the creation of a new person with a lifespan of 100 years. We will be motivated to prefer the former scenario because it is difficult for us to feel its relevance to the latter.

I currently route around this by being an ethical egoist, though I admit that I still have a lot to learn when it comes to metaethics. (And I 'm not just leaving it at "I still have a lot to learn", either - I'm taking active steps to learn more, and I'm not just signalling that, and I'm not just signalling that I'm not signalling that, etc.)!

Why does one have to be better than the other?

But in my thought experiment, average utility remains unchanged.

The average utility, counting only those two people, is unchanged (as long as we assume that life from 0-100 is as pleasurable as life from 100-200). But firstly the utility of other humans should be taken into account; the loved ones of the person already living, the likely pleasure given to others by younger people in comparison to older people, the expected resources consumed etc.

But perhaps your thought experiment supposes that these expected utility calculations all happen to be equal in either case, too. In that case, surely there is still your own utility to be taken into consideration!

I don't know much about utilitarianism (generally I regard all attempts at inventing moral formulae to describe human values to be hopeless, because we aren't as a matter of fact reflectively consistent), but presumably in utilitarianism you are allowed to have aesthetic values apart from the value attached to pleasure and suffering in others (otherwise I conclude that utilitarianism is one of the less sensible such formulae). Therefore if the utility of others is the same either way, your personal non-altruistic aesthetic values are the deciding factor (and the question of how these are to be balanced with the value attached to the utility of other people is irrelevant in this case). Clearly your non-altruistic values do prefer the idea of life extension, so I don't see any problem here.