vegan advocacy [...] has a lot of ambiguous effects on wild animal suffering (which don't seem more "speculative", given the fairly robust-seeming arguments Tomasik has written about)

I'd be curious to hear more about this. What are the robust-seeming arguments? 

Thanks for writing this, Anthony!

I find myself wondering what counts as "speculative" vs not. Here are some guesses at sufficient conditions for speculativeness:

An effect is speculative if it is highly sensitive to:

• Physical or metaphysical assumptions that are themselves speculative
  • E.g., theories of cosmology, solutions to the measurement problem in quantum mechanics, theories of consciousness
• Facts about the world / mechanisms we're presently unaware of
  • E.g., improvements to SOTA AI architectures and training methods, entirely new mechanisms for extinction, facts challenging our current understanding of macroeconomics, biology, etc 

Thanks for writing this, that was an interesting read!

I will continue to illustrate with separate components, since that's more general and can capture deeper uncertainty and worse moral uncertainty

Whether or not you think you can add separate components seems pretty important for the hedging approach. 

Indeed, if a portfolio dominates the default on each individual component, then some interventions in the portfolio must dominate the default overall.^[1] So if you can compare interventions based on their total effects, the existence of such portfolios imply that some interventions dominate the default. Intuitively then, you would prefer investing in one of those interventions over hedging? (Although a complication I haven't thought about is that you should compare interventions with one another too, unless you think the default has a privileged status.)

Given the above, a worry I have is that the hedging approach doesn't save us from cluelessness, because we don't have access to an overall-better-than-the-default intervention to begin with.

To put my two questions in more concrete terms:

1. In your example, how do we become confident that the wild animal intervention is worst-case net-positive compared to the default?
2. Given that we're confident about (1), why prefer a portfolio to investing solely in the wild animal intervention?

1. ^{^}

   Sketch of proof: Let $w_i$ be ressources allocated to intervention $A_i$ in your portfolio, and let $a_i^j$ be the worst-case effect of intervention $A_i$ on component $j$. Then

   $$\sum _{i,j}{w}_i{a}_i^j=\sum _i\left(\sum _j{a}_i^j\right)w_i\ge 0$$

   and there is an intervention for which worst-case effects are in aggregate non-negative.