Suppose you had the chance to save the life of one sparrow, but doing so kills you with probability p. For what values of p would you do so?

If the answer is only when p=0, then your value of sparrows should never affect your choices, because it will always be dominated by the greater probability of your own welfare.

I think this is more due to diminishing marginal returns for the amount of sparrows in existence, to be honest...

Jokes aside, you are offering a very persuasive argument; I'd be curious to know how you figure out what tier certain values are and whether you ever have reason to (a) change your mind about said tier or (b) create new tiers altogether?

Interesting analogy. If we accept that utilities are additive, then there is presumably a number of sparrows worth killing for. (Of course, there may be a limit on all possible sparrows or sparrow utilities may be largely due to species preservation or something. As an ethics-based vegetarian, however, I can simply change it to "sparrows tortured.) I would be uncomfortable trying to put a number on it, what with the various sacred value conflicts involved, but I accept that a Friendly AI (even one Friendly only to me) would know and act on it.

Maslow's Pyramid is not intended as some sort of alternative to utilitarianism, it's a description of how we should prioritize the needs of humans. An imperfect one, of course, but better than nothing.

How sure? Based on what? What would persuade you otherwise?

If not, then you are saying that not all goals reduce to a number on a single metric, (...)

Simply false AFAIK. There is a mathematical way to express as a single-number metric every tiered system I've ever been capable of conceiving, and I suspect those I haven't also have such expressions with more mathematics I might not know.

So, I don't know if the grandparent was saying that, but I assume it wasn't, and if it was implied somewhere and I missed it then it certainly is false.

But then again, I may simply be interpreting your words uncharitably. I assume you're already aware that Maslow's can also be reduced to a single number formula.

A more interesting question than maximizing numbers of sparrows, however, is maximizing other value-factors. Suppose instead of imagining a number of sparrows sufficiently large for which you would trade a human you care about, you imagine a number of different minimum-sufficiency-level values being traded off for that "higher-tiered" life.

One human against a flock of sparrows large enough to guarantee the survival of the species is easy enough. Even the sparrow species doesn't measure up against a human, or at least that's what I expect you'd answer.

Now measure it up against a flock of each species of birds, on pain of extinction of birds (but let's magically handwave away the ecosystem impacts of this - suppose we have advanced technology to compensate for all possible effects).

Now against a flock of each species of birds, a group of each species of nonhuman mammals, a school of each species of fish, a colony of each species of insects, and so forth throughout the entire fauna and flora of the planet - or of all known species of life in the universe. Again we handwave - we can make food using the power of Science and so on.

Now against the same, but without the handwaving. The humans you care about are all fine and healthy, but the world they live in is less interesting, and quite devastated, but Science keeps y'all healthy and stuff.

Now against that, plus having actual human bodies. You're all jarbrains.

Feel free to keep going, value by value, until you reach a sufficient tradeoff or accept that no amount of destructive alteration to the universe will ever compare to the permanent loss of consciousness of your loved ones, and therefore you'd literally do everything and anything, up to and including warping space and time and sacrificing knowledge or memory or thinking-power or various qualia or experience or capacity for happiness or whatever else you can imagine, all traded for this one absolute value.

"Life/consciousness of loved ones" can also be substituted for whichever is your highest-tiered value if different.