How much more optimistic would you be about research on i) the welfare of soil animals and microorganisms, and ii) comparisons of (expected hedonistic) welfare across species if you strongly endorsed expectational total hedonistic utilitarianism, moral realism, and precise probabilitites, and ignored acausal effects, and effects after 100 years?

Based on age-structured mortality models for affected species like song sparrows, collision victims who survive gain approximately 1–2 additional years of life

Do you mean the life expectancy of birds who would avoid collisions thanks to bird-safe glass would increase by 1 to 2 years? I assume collision victims who survive have a lower life expectancy than birds who avoid collisions thanks to the bird-safe glass. @Luke Hecht may have thoughts on this.

Thanks for the follow-up, Soem.

Nonetheless, I think some interventions we consider, such as alternative proteins, bycatch mitigation, and fish meal reliance can also benefit (wild or farmed) animals, albeit not per se in the most cost-effective way.

I think it is important to explicitly give weight to welfare considerations. I do not expect any of the above to robustly increase welfare. However, discussing them in the context of increasing welfare could contribute towards strengthening the wild animal welfare movement.

What I would actually do depends a lot on the situation, but I have a hard time imagining scenarios where it matters whether the probability of Jones having commited the crime is 40 % or 60 %. So I might not even try to decrease the uncertainty about this, and just focus on other considerations. What would maximise the impact of my future donations and work? What information would I have about Jones and Smith? Who would have the greater potential to contribute to a better world? How much time would I have to decide? Would I be accountable in some way for my decision? If so, how would my decision be assessed? What would be the potential consequences of people concluding I made a good or bad decision? How were decisions like mine assessed in the past?

Do you (Michael) see your views about precise and imprecise credences significantly affecting what you would actually do in the real world in a scenario where you had to blame Jones or Smith? Considerations like the ones I mentioned above would matter mode? I may be dodging your question, but I am ultimately interested in making better decisions in the real world. So I think it makes sense to discuss precise and imprecise credences in the context of realistic scenarios.

I could report 50 % for 68 and 69 eyewitnesses, but this does not necessarily imply I am insensitive to small changes in the number of eyewitnesses. In practice, I would be reporting my best guess rounded to the closest multiple of 0.1 or so. So I believe the reported value being exactly the same would only mean my best guesses differ by less than 10 pp, not that they are exactly the same. I would say the mean of the (rounded) reported best guesses for a given number of eyewitnesses tends to the (precise) underlying best guess as the number of reports increases. If I could hypothetically encounter the question in practically the same situation for 1 M times, I could easily see the mean of my reported values for 68 and 69 eyewitnesses being different. 

The reasons you mentioned for gathering strong evidence not being possible (or being very difficult) apply to some extent to efforts increasing human welfare, but humans have probably still made progress on increasing human welfare over the past 200 years or so? Can one be confident similar progress cannot be extended to non-humans?

I agree research can backfire. However, at least historically, doing research on the sentience of animals, and on how to increase their welfare has mostly been beneficial for the target animals?

I would simply say the expected mass is practically (not exactly) the same given the evidence available to me, and consider gathering additional evidence depending on how much I expected this to change future decisions. Likewise for altruistic interventions among which comparisons of the expected change in welfare feel very arbitrary.

I'd also be keen to get your response to this (and also this, if you have the time.)

I have replied to both comments.

I think there's a lot that could change if you very seriously weighed others' actual or possible direct impressions/intuitions without heavily privileging your own, before we even get into the question of precise vs imprecise credences. Epistemic modesty is going to do a lot of work first.

Thanks for elaborating on this. I imagine I could arrive to different (practical) priorities if I changed my mind about the topics you listed. At the same time, my more foundational philosophical views have historically changed very little. Investigations about empirical matters have updated my priorities a lot more. So I would be curious to know if you think there are areas which are more amenable to empirical investigation, and where I am not giving enough consideration to the views of others.

I'm clueless about whether crops or nature is better for wild animals, even though I'm suffering-focused

I agree it is very unclear whether increasing cropland is good or bad, even for suffering-focussed people.

Hi Michael.

It seems bad if we're basing how to do the most good on whims and biases.

I agree. However, in cases where priors are playing a crucial role, one should simply prioritise gathering more evidence until there is reasonable convergence about what to do (among a given group of people, for a particular decision)?

I would be able to subjectively compare the mass of the 2 objects with more evidence. Some comparisons may not be feasible with currently available evidence, but the degree of imprecision should be set by what is physically possible?