…a toy example involving some numbers. In doing this, I want to emphasize that the numbers I have chosen are purely for illustrative purposes. I am not claiming that they are realistic. Whether they are, or not, is irrelevant to my point.
Suppose that we have some funds with which we want to do good. We have two ways of spending those funds: option one, Poverty Elimination; or option two, Asteroid Deflector.
Suppose that if we do Poverty Elimination, we will, with certainty, significantly improve the quality of life of one hundred million people in desperate need.
More particularly, we would transform their lives from ones that would be short, and filled with great misery, into ones that would be long, and very well off. So, for the sake of the example, let us say that if we don’t do Poverty Elimination, each person will live only 15 years, at level -50 (utiles, meaning that their lives would be significantly below the level at which life ceases to be worth living), while if we do Poverty Elimination, each person will live for 75 years at level 100 (utiles, meaning that their lives would be well worth living).
We can calculate the expected value of Poverty Elimination as 825 billion years of utility. ((50(utiles)*15(years)*100 million(people)) + (100(utiles)*75(years)*100 million(people)).) Undeniably, that is a lot of expected good.
In the real world, of course, there may be all sorts of further consequences from lifting 100 million people out of poverty, and keeping them alive for 75 years, rather than having them all die before their fifteenth birthday. Many of these effects will be positive, others may be negative. However, for the purposes of keeping this example as clean, and clear, as possible, let us suppose that there are no other effects, positive or negative, from adopting Poverty Elimination, other than those described above. So, as stated, in this example, the total amount of expected value of Poverty Elimination is 825 billion years of utility.
Next, suppose that scientists have calculated that in any given year, there is a one in 50 million chance that all life on Earth will be wiped out due to collision with a giant asteroid. This means that there is a one in 250,000 chance that life will be wiped out by an asteroid collision sometime in the next 200 years. If one spends one’s funds on Asteroid Deflector, there is only a one in a thousand chance that it will work. Is it worth spending money on Asteroid Deflector, which would only reduce the odds of human extinction due to an asteroid collision from one in 250,000 sometime in the next 200 years (0.000004 percent chance) to one in 250,250 sometime in the next 200 years (~0.000003996 percent chance)? That is, is spending the money on Asteroid Deflector worth increasing the odds of our surviving for the next 200 years by a mere four billionths (0.000000004)?
The answer to the preceding question depends on all sorts of factors that are difficult to accurately estimate. However, if we assume that the likelihood of our going extinct in the next 200 years due to an asteroid collision is not connected to the likelihood of our going extinct from other causes, and also assume, more controversially, that reducing the chance of extinction from any given type of extinction event by n percent reduces the total chance of extinction by n percent, then one might think about this issue along the following lines.
It is reasonable to suppose that if we manage to survive the next 200 years, there will be an explosion of developments in knowledge, creativity, morality, politics, technology, medicine, and so on. This explosion will enable humans to live vastly longer lives and, as importantly, vastly better lives. It will also allow humans to explore other planets, and possibly other galaxies, and hence to live in vastly greater numbers. It will also allow humans to effectively anticipate and avoid future existential risks, so members of our species will be able to continue to exist, perhaps spread throughout the solar system or galaxies, for a very long time into the future. Given how bright the future might be for us as a species, it might seem extremely important to try to ensure that we manage to attain that future.
How important?
Well, for the sake of the example, let us suppose that the following were true. If we manage to avoid destroying ourselves in the next 200 years, or being destroyed by a virus, asteroid, or some other cataclysmic disaster, then there is at least a 90 percent probability that the future will include at least 100 billion humans, living an average of 200 years each, at a very high quality of, say, 200 utiles throughout their lives, for a total of at least 500 million years. The expected value of that outcome would be at least 9,000 billion billion years of utility (0.9(the probability of the desirable future)*100 billion(people who would be living in that future at any given time)*200(utiles, the quality of each person’s life at each moment of their life)*500 million(years of existence such humans would live)). That is an extraordinary amount of utility which, by hypothesis, hangs in the balance, depending on whether we survive the next 200 years. So, even if funding Asteroid Deflector only increases the chances of our attaining that golden future by 0.000000004, that would still have an expected value of 3.6 million million years of utility, or 36,000 billion years of utility. That, of course, is considerably more than the expected value of Poverty Elimination, which we calculated at 825 billion people years of utility. In fact, given these figures, the expected value of Asteroid Deflector would be over 43 times greater than the expected value of Poverty Elimination. Therefore, in accordance with Expected Utility Theory, we should fund Asteroid Deflector.
Suppose, next, that further funds become available that we could use to help the one billion people with terrible life prospects. However, we also learn that there is a one in 20 chance that a crucial component in Asteroid Deflector will fail, and that if we fund Backup Machine One we can protect against this failure. By the lights of Expected Utility Theory, we should fund Backup Machine One, rather than Poverty Elimination, since the expected value of funding the former will be 1,800 billion years of utility (0.05 (the chance that we will need Backup Machine One)*36,000 billion years of utility(the amount of good that is at stake if Asteroid Deflector fails and we don’t have Backup Machine One)), while the expected utility of funding the latter will still “only” be 825 billion years of utility.
Next, suppose that we once again find ourselves with additional resources that would enable us to fund Poverty Elimination. However, we now learn that there is a 50 percent chance that Backup Machine One will fail, and that we could build Backup Machine Two to protect against this. By the lights of Expected Utility Theory, we should then fund Backup Machine Two, rather than Poverty Elimination, since the expected value of funding the former will be 900 billion years of utility (0.5(the chance that we will need Backup Machine Two)*1,800 billion years of utility(the amount of good that is at stake if both Asteroid Deflector fails and Backup Machine One fail, and we don’t have Backup Machine Two)), while the expected utility of funding the latter will still “only” be 825 billion people years of utility.
This toy example helps illustrate how considerations of vast numbers of possible future people, all of whom might live much better, longer, lives than anyone alive today, can utterly swamp the urgent claims of very large numbers of actual people who are suffering terribly. This can happen if one allows one’s judgments about which endeavors to support to be driven by the “do the most (expected) good” approach of Effective Altruism, and if one follows Expected Utility Theory in determining the expected good (or value, or utility) of one’s actions.
Effective Altruists who believe that we should focus on existential risk may quibble with the details of my example, or the way that I have put some of my claims, but they should not, I think, object to the gist of my claims. To the contrary, they should insist that the sorts of considerations I have offered here are no objection to their views, but rather an explanation, and vindication, of their views. With all due respect, however—and I really do respect the people who advocate the position in question—I can’t, myself, accept such a view. I do believe, and have argued in print, that it is very important to try to ensure that high quality life exist as far into the future as possible.2 In addition, I readily accept that in thinking about such issues, there is much to be said for considering the expected value of one’s different alternatives. Even so, in my judgment, Expected Utility Theory is a tool, nothing more, which needs to be employed carefully. It can generate a mathematical truth about the relevant amounts of an artificial construct—expected utility—that we can attach to different options. But it cannot tell us how much weight, if any, to attach to that mathematical truth in deciding what we ought to do.
To be clear, and fair, real-world Effective Altruists who believe we should focus on existential risk are not arguing that we should be spending money on projects like Asteroid Deflector. Indeed, they would argue, as Nick Beckstead pointed out in correspondence, that Asteroid Deflector “may be among the least effective of existential risk interventions, and that the Effective Altruist community thinks that it’s possible to get thousands or millions of times better [expected] returns by focusing on nuclear weapons policy, artificial intelligence, and threats to liberal democracy.” Indeed, it is worth recalling, as previously noted in Section 1.7, that Will MacAskill believes that thoughtful efforts to reduce global catastrophic risks “have a better cost-effectiveness than organizations like AMF [Against Malaria Foundation, long rated as one of the top global aid charities by GiveWell and The Life You Can Save], even if we just consider the potential deaths of people over the next 100 years (emphasis added).” If true, this is important. However, it does not undermine the point of this example.
I am not disputing whether there is good reason to devote significant resources to reducing existential risks. There is. Nor am I disputing whether considerations of Expected Utility Theory have an important role to play in our thinking about how to distribute our resources. They do. However, none of this changes the fact that if we let our thinking about such issues be driven by Expected Utility Theory, rather than merely partly guided by it, then even after we have addressed all of the vastly more cost-effective approaches to reducing existential risk, we should still be spending money on projects like Asteroid Deflector, rather than Poverty Elimination, because the former has a greater expected utility than the latter. At this point, I believe, we have, in the name of Expected Utility Theory, effectively abandoned the needy, for the sake of a far-flung future filled with well-off individuals; a future whose contours may or may not look anything like we now hope it will, and whose realization may or may not turn on the decisions we now make.
My own view is that adherence to Expected Utility Theory will drive us off the rails if, based on it, we choose to fund Asteroid Deflector rather than Poverty Elimination. Moreover, in my judgment, we go further off the rails if we later fund Backup Machine One, and still further off the rails if we subsequently fund Backup Machine Two. Faced with the choice of substantially helping one hundred million people who are desperately in need now, or supporting a one in a thousand chance to prevent an occurrence of something which would itself only have a one in 250,000 chance of occurring, so as to thereby ever-so-slightly increase the possibility of lots of distantly future people living incredibly great lives, I prioritize the former over the latter. And if I did postpone meeting the urgent needs of some of the world’s worst-off, to ever-so-slightly increase the possibility of a future, lengthy, Eden for our descendants, I certainly wouldn’t do this a second time, let alone a third time.
This is not, I believe, because I fail to understand how the math works out. I simply fail to accept that what we ought to do, in such cases, is determined by the math. There is, as I argue throughout this book, so much more to being good in a world of need, than merely “doing the most expected good” that one can.
I'd also like to reiterate the arguments Larry Temkin gave against international aid, since the post doesn't cover them. I'm not sure if I'm convinced by these arguments, but I do find them reasonable and worth serious consideration.