When maximizing utility doesn’t

Jun 4 JDN 2460100

Expected utility theory behaves quite strangely when you consider questions involving mortality.

Nick Beckstead and Teruji Thomas recently published a paper on this: All well-defined utility functions are either reckless in that they make you take crazy risks, or timid in that they tell you not to take even very small risks. It’s starting to make me wonder if utility theory is even the right way to make decisions after all.

Consider a game of Russian roulette where the prize is $1 million. The revolver has 6 chambers, 3 with a bullet. So that’s a 1/2 chance of $1 million, and a 1/2 chance of dying. Should you play?

I think it’s probably a bad idea to play. But the prize does matter; if it were $100 million, or $1 billion, maybe you should play after all. And if it were $10,000, you clearly shouldn’t.

And lest you think that there is no chance of dying you should be willing to accept for any amount of money, consider this: Do you drive a car? Do you cross the street? Do you do anything that could ever have any risk of shortening your lifespan in exchange for some other gain? I don’t see how you could live a remotely normal life without doing so. It might be a very small risk, but it’s still there.

This raises the question: Suppose we have some utility function over wealth; ln(x) is a quite plausible one. What utility should we assign to dying?


The fact that the prize matters means that we can’t assign death a utility of negative infinity. It must be some finite value.

But suppose we choose some value, -V, (so V is positive), for the utility of dying. Then we can find some amount of money that will make you willing to play: ln(x) = V, x = e^(V).

Now, suppose that you have the chance to play this game over and over again. Your marginal utility of wealth will change each time you win, so we may need to increase the prize to keep you playing; but we could do that. The prizes could keep scaling up as needed to make you willing to play. So then, you will keep playing, over and over—and then, sooner or later, you’ll die. So, at each step you maximized utility—but at the end, you didn’t get any utility.

Well, at that point your heirs will be rich, right? So maybe you’re actually okay with that. Maybe there is some amount of money ($1 billion?) that you’d be willing to die in order to ensure your heirs have.

But what if you don’t have any heirs? Or, what if we consider making such a decision as a civilization? What if death means not only the destruction of you, but also the destruction of everything you care about?

As a civilization, are there choices before us that would result in some chance of a glorious, wonderful future, but also some chance of total annihilation? I think it’s pretty clear that there are. Nuclear technology, biotechnology, artificial intelligence. For about the last century, humanity has been at a unique epoch: We are being forced to make this kind of existential decision, to face this kind of existential risk.

It’s not that we were immune to being wiped out before; an asteroid could have taken us out at any time (as happened to the dinosaurs), and a volcanic eruption nearly did. But this is the first time in humanity’s existence that we have had the power to destroy ourselves. This is the first time we have a decision to make about it.

One possible answer would be to say we should never be willing to take any kind of existential risk. Unlike the case of an individual, when we speaking about an entire civilization, it no longer seems obvious that we shouldn’t set the utility of death at negative infinity. But if we really did this, it would require shutting down whole industries—definitely halting all research in AI and biotechnology, probably disarming all nuclear weapons and destroying all their blueprints, and quite possibly even shutting down the coal and oil industries. It would be an utterly radical change, and it would require bearing great costs.

On the other hand, if we should decide that it is sometimes worth the risk, we will need to know when it is worth the risk. We currently don’t know that.

Even worse, we will need some mechanism for ensuring that we don’t take the risk when it isn’t worth it. And we have nothing like such a mechanism. In fact, most of our process of research in AI and biotechnology is widely dispersed, with no central governing authority and regulations that are inconsistent between countries. I think it’s quite apparent that right now, there are research projects going on somewhere in the world that aren’t worth the existential risk they pose for humanity—but the people doing them are convinced that they are worth it because they so greatly advance their national interest—or simply because they could be so very profitable.

In other words, humanity finally has the power to make a decision about our survival, and we’re not doing it. We aren’t making a decision at all. We’re letting that responsibility fall upon more or less randomly-chosen individuals in government and corporate labs around the world. We may be careening toward an abyss, and we don’t even know who has the steering wheel.

Why risking nuclear war should be a war crime

Nov 19, JDN 2458078

“What is the value of a human life?” is a notoriously difficult question, probably because people keep trying to answer it in terms of dollars, and it rightfully offends our moral sensibilities to do so. We shouldn’t be valuing people in terms of dollars—we should be valuing dollars in terms of their benefits to people.

So let me ask a simpler question: Does the value of an individual human life increase, decrease, or stay the same, as we increase the number of people in the world?

A case can be made that it should stay the same: Why should my value as a person depend upon how many other people there are? Everything that I am, I still am, whether there are a billion other people or a thousand.

But in fact I think the correct answer is that it decreases. This is for two reasons: First, anything that I can do is less valuable if there are other people who can do it better. This is true whether we’re talking about writing blog posts or ending world hunger. Second, and most importantly, if the number of humans in the world gets small enough, we begin to face danger of total permanent extinction.

If the value of a human life is constant, then 1,000 deaths is equally bad whether it happens in a population of 10,000 or a population of 10 billion. That doesn’t seem right, does it? It seems more reasonable to say that losing ten percent should have a roughly constant effect; in that case losing 1,000 people in a population of 10,000 is equally bad as losing 1 billion in a population of 10 billion. If that seems too strong, we could choose some value in between, and say perhaps that losing 1,000 out of 10,000 is equally bad as losing 1 million out of 1 billion. This would mean that the value of 1 person’s life today is about 1/1,000 of what it was immediately after the Toba Event.

Of course, with such uncertainty, perhaps it’s safest to assume constant value. This seems the fairest, and it is certainly a reasonable approximation.

In any case, I think it should be obvious that the inherent value of a human life does not increase as you add more human lives. Losing 1,000 people out of a population of 7 billion is not worse than losing 1,000 people out of a population of 10,000. That way lies nonsense.

Yet if we agree that the value of a human life is not increasing, this has a very important counter-intuitive consequence: It means that increasing the risk of a global catastrophe is at least as bad as causing a proportional number of deaths. Specifically, it implies that a 1% risk of global nuclear war is worse than killing 10 million people outright.

The calculation is simple: If the value of a human life is a constant V, then the expected utility (admittedly, expected utility theory has its flaws) from killing 10 million people is -10 million V. But the expected utility from a 1% risk of global nuclear war is 1% times -V times the expected number of deaths from such a nuclear war—and I think even 2 billion is a conservative estimate. (0.01)(-2 billion) V = -20 million V.

This probably sounds too abstract, or even cold, so let me put it another way. Suppose we had the choice between two worlds, and these were the only worlds we could choose from. In world A, there are 100 leaders who each make choices that result in 10 million deaths. In world B, there are 100 leaders who each make choices that result in a 1% chance of nuclear war. Which world should we choose?

The choice is a terrible one, to be sure.

In world A, 1 billion people die.

Yet what happens in world B?

If the risks are independent, we can’t just multiply by 100 to get a guarantee of nuclear war. The actual probability is 1-(1-0.01)^100 = 63%. Yet even so, (0.63)(2 billion) = 1.26 billion. The expected number of deaths is higher in world B. Indeed, the most likely scenario is that 2 billion people die.

Yet this is probably too conservative. The risks are most likely positively correlated; two world leaders who each take a 1% chance of nuclear war probably do so in response to one another. Therefore maybe adding up the chances isn’t actually so unreasonable—for all practical intents and purposes, we may be best off considering nuclear war in world B as guaranteed to happen. In that case, world B is even worse.

And that is all assuming that the nuclear war is relatively contained. Major cities are hit, then a peace treaty is signed, and we manage to rebuild human civilization more or less as it was. This is what most experts on the issue believe would happen; but I for one am not so sure. The nuclear winter and total collapse of institutions and infrastructure could result in a global apocalypse that would result in human extinctionnot 2 billion deaths but 7 billion, and an end to all of humanity’s projects once and forever This is the kind of outcome we should be prepared to do almost anything to prevent.

What does this imply for global policy? It means that we should be far more aggressive in punishing any action that seems to bring the world closer to nuclear war. Even tiny increases in risk, of the sort that would ordinarily be considered negligible, are as bad as murder. A measurably large increase is as bad as genocide.

Of course, in practice, we have to be able to measure something in order to punish it. We can’t have politicians imprisoned over 0.000001% chances of nuclear war, because such a chance is so tiny that there would be no way to attain even reasonable certainty that such a change had even occurred, much less who was responsible.

Even for very large chances—and in this context, 1% is very large—it would be highly problematic to directly penalize increasing the probability, as we have no consistent, fair, objective measure of that probability.

Therefore in practice what I think we must do is severely and mercilessly penalize certain types of actions that would be reasonably expected to increase the probability of catastrophic nuclear war.

If we had the chance to start over from the Manhattan Project, maybe simply building a nuclear weapon should be considered a war crime. But at this point, nuclear proliferation has already proceeded far enough that this is no longer a viable option. At least the US and Russia for the time being seem poised to maintain their nuclear arsenals, and in fact it’s probably better for them to keep maintaining and updating them rather than leaving decades-old ICBMs to rot.

What can we do instead?

First, we probably need to penalize speech that would tend to incite war between nuclear powers. Normally I am fiercely opposed to restrictions on speech, but this is nuclear war we’re talking about. We can’t take any chances on this one. If there is even a slight chance that a leader’s rhetoric might trigger a nuclear conflict, they should be censored, punished, and probably even imprisoned. Making even a veiled threat of nuclear war is like pointing a gun at someone’s head and threatening to shoot them—only the gun is pointed at everyone’s head simultaneously. This isn’t just yelling “fire” in a crowded theater; it’s literally threatening to burn down every theater in the world at once.

Such a regulation must be designed to allow speech that is necessary for diplomatic negotiations, as conflicts will invariably arise between any two countries. We need to find a way to draw the line so that it’s possible for a US President to criticize Russia’s intervention in the Ukraine or for a Chinese President to challenge US trade policy, without being accused of inciting war between nuclear powers. But one thing is quite clear: Wherever we draw that line, President Trump’s statement about “fire and fury” definitely crosses it. This is a direct threat of nuclear war, and it should be considered a war crime. That reason by itself—let alone his web of Russian entanglements and violations of the Emoluments Clause—should be sufficient to not only have Trump removed from office, but to have him tried at the Hague. Impulsiveness and incompetence are no excuse when weapons of mass destruction are involved.

Second, any nuclear policy that would tend to increase first-strike capability rather than second-strike capability should be considered a violation of international law. In case you are unfamiliar with such terms: First-strike capability consists of weapons such as ICBMs that are only viable to use as the opening salvo of an attack, because their launch sites can be easily located and targeted. Second-strike capability consists of weapons such as submarines that are more concealable, so it’s much more likely that they could wait for an attack to happen, confirm who was responsible and how much damage was done, and then retaliate afterward.
Even that retaliation would be difficult to justify: It’s effectively answering genocide with genocide, the ultimate expression of “an eye for an eye” writ large upon humanity’s future. I’ve previously written about my Credible Targeted Conventional Response strategy that makes it both more ethical and more credible to respond to a nuclear attack with a non-nuclear retaliation. But at least second-strike weapons are not inherently only functional at starting a nuclear war. A first-strike weapon can theoretically be fired in response to a surprise attack, but only before the attack hits you—which gives you literally minutes to decide the fate of the world, most likely with only the sketchiest of information upon which to base your decision. Second-strike weapons allow deliberation. They give us a chance to think carefully for a moment before we unleash irrevocable devastation.

All the launch codes should of course be randomized onetime pads for utmost security. But in addition to the launch codes themselves, I believe that anyone who wants to launch a nuclear weapon should be required to type, letter by letter (no copy-pasting), and then have the machine read aloud, Oppenheimer’s line about Shiva, “Now I am become Death, the destroyer of worlds.” Perhaps the passphrase should conclude with something like “I hereby sentence millions of innocent children to death by fire, and millions more to death by cancer.” I want it to be as salient as possible in the heads of every single soldier and technician just exactly how many innocent people they are killing. And if that means they won’t turn the key—so be it. (Indeed, I wouldn’t mind if every Hellfire missile required a passphrase of “By the authority vested in me by the United States of America, I hereby sentence you to death or dismemberment.” Somehow I think our drone strike numbers might go down. And don’t tell me they couldn’t; this isn’t like shooting a rifle in a firefight. These strikes are planned days in advance and specifically designed to be unpredictable by their targets.)

If everyone is going to have guns pointed at each other, at least in a second-strike world they’re wearing body armor and the first one to pull the trigger won’t automatically be the last one left standing.

Third, nuclear non-proliferation treaties need to be strengthened into disarmament treaties, with rapid but achievable timelines for disarmament of all nuclear weapons, starting with the nations that have the largest arsenals. Random inspections of the disarmament should be performed without warning on a frequent schedule. Any nation that is so much as a day late on their disarmament deadlines needs to have its leaders likewise hauled off to the Hague. If there is any doubt at all in your mind whether your government will meet its deadlines, you need to double your disarmament budget. And if your government is too corrupt or too bureaucratic to meet its deadlines even if they try, well, you’d better shape up fast. We’ll keep removing and imprisoning your leaders until you do. Once again, nothing can be left to chance.

We might want to maintain some small nuclear arsenal for the sole purpose of deflecting asteroids from colliding with the Earth. If so, that arsenal should be jointly owned and frequently inspected by both the United States and Russia—not just the nuclear superpowers, but also the only two nations with sufficient rocket launch capability in any case. The launch of the deflection missiles should require joint authorization from the presidents of both nations. But in fact nuclear weapons are probably not necessary for such a deflection; nuclear rockets would probably be a better option. Vaporizing the asteroid wouldn’t accomplish much, even if you could do it; what you actually want to do is impart as much sideways momentum as possible.

What I’m saying probably sounds extreme. It may even seem unjust or irrational. But look at those numbers again. Think carefully about the value of a human life. When we are talking about a risk of total human extinction, this is what rationality looks like. Zero tolerance for drug abuse or even terrorism is a ridiculous policy that does more harm than good. Zero tolerance for risk of nuclear war may be the only hope for humanity’s ongoing survival.

Throughout the vastness of the universe, there are probably billions of civilizations—I need only assume one civilization for every hundred galaxies. Of the civilizations that were unwilling to adopt zero tolerance policies on weapons of mass destruction and bear any cost, however unthinkable, to prevent their own extinction, there is almost boundless diversity, but they all have one thing in common: None of them will exist much longer. The only civilizations that last are the ones that refuse to tolerate weapons of mass destruction.