Vasco Grilo🔸 comments on Rethink Priorities’ Welfare Range Estimates

[Vasco Grilo🔸]

What is the period of time to which “most intense” refers to? Any period of time, or the typical lifespan of the species? If the former, the welfare ranges practically refer to the intensities of very short experiences (for example, the worst possible second is worse than a random second of the worst possible minute).

[Bob Fischer]

We discuss this in the book here. The summary:

...we’ll have to settle for some rough, intuitive sense of the space of possibilities relative to which we’re evaluating welfare ranges. We might think of them as the “realistic biological possibilities,” or something to that effect, which seems like the set of possibilities to which general physiological, cognitive, and behavioral traits might be relevant (as, again, we’ll discuss Chapters 5–7). Very roughly, these possibilities are the ones that we take to be realistic ways things could turn out for an individual based on our best biological theories and our understanding of their biological characteristics.

Of course, even if we have a tolerably good understanding of the “realistic biological possibilities,” it remains the case that a “tolerably good understanding” leaves plenty of room for disagreement about specific cases, including many that may be practically relevant. So, we aren’t going to get the fine-grained, context-sensitive picture we might have wanted—or, at least, not without further discussion about how to extend the framework that we’re developing. However, whatever the limits of this approach, it does reasonably well overall. It does a better job of limiting our attention to relevant possibilities (in one sense of “relevant”) than we’d get by considering the logical, metaphysical, or physical possibilities. Insofar as we can secure welfare-relevant biological knowledge, it does reasonably well on the epistemic criterion, and while more coarse-grained than we might like, it may still prove useful in many practical contexts. After all, the goal here is to improve interspecies welfare comparisons relative to armchair speculation. If that method is bad enough, then the bar for claiming improvement is low.

[Vasco Grilo🔸]

Thanks, Bob! Based on that, my understanding is that the welfare ranges refer to differences between the welfare per unit time of the best and worst moments that could be realistically experieced (that are “realistic biological possibilities”).