Unless you have crazy-long ASI timelines, you should choose life-saving interventions (e.g. AMF, New Incentives) over welfare-increasing interventions (e.g. GiveDirectly, Helen Keller International). This is because you expect that ASI will radically increase both longevity and welfare.

To illustrate, suppose we're choosing how to donate $5000 and have two options:

(AMF) Save the life of a 5-year-old in Zambia who would otherwise die from malaria.

(GD) Improve the lives of five families in Kenya by sending each family one year's salary ($1000).

Suppose that, before considering ASI, you are indifferent between (AMF) and (GD). The ASI consideration should then favour (AMF) because:

1. Before considering ASI, you are underestimating the benefit to the Zambian child. You are underestimating both how long they will live if they avoid malaria and how good their life will be.
2. Before considering ASI, you are overestimating the benefit to the Kenyan families. You are overestimating how large the next decade is as a proportion of their lives and how much you are improving their aggregate lifetime welfare.

I find this pretty intuitive, but you might find the mathematical model below helpful. Please let me know if you think I'm making either a mistake, either ethically or factually.

Mathematical setup

Assume a person-affecting axiology where how well a person's life goes is logarithmic in their total lifetime welfare. Lifetime welfare is the integral of welfare over time. The benefit of an intervention is how much better their life goes: the difference in log-lifetime-welfare with and without the intervention.

Assume ordinary longevity is 80 years, ASI longevity is 1000 years, ordinary welfare is 1 unit/year, ASI welfare is 1000 units/year, and ASI arrives 50 years from now with probability p. Note that these numbers are completely made up -- I think ASI longevity and ASI welfare are underestimates.

AMF: Saving the Zambian child

Consider the no-ASI scenario. Without intervention the child dies aged 5, so their lifetime welfare is 5. With intervention the child lives to 80, so their lifetime welfare is 80. The benefit is log(80) − log(5) = 2.77.

Consider the ASI scenario. Without intervention the child still dies aged 5, so their lifetime welfare is 5. With intervention the child lives to 1000, accumulating 50 years at welfare 1 and 950 years at welfare 1000, so their lifetime welfare is 50 + 950,000 = 950,050. The benefit is log(950,050) − log(5) = 12.15.

The expected benefit is (1−p) × 2.77 + p × 12.15.

GD: Cash transfers to Kenyan families

Assume 10 beneficiaries (five families, roughly 2 adults each). Each person will live regardless of the intervention; GD increases their welfare by 1 unit/year for the rest of their lives (or until ASI arrives, at which point ASI welfare dominates).

Consider the no-ASI scenario. Without intervention each person has lifetime welfare 80. With intervention each person has lifetime welfare 160. The benefit per person is log(160) − log(80) = 0.69.

Consider the ASI scenario. Without intervention each person has lifetime welfare 950,050. With intervention each person has lifetime welfare 950,100 (the extra 50 units from pre-ASI doubling). The benefit per person is log(950,100) − log(950,050) = 0.000053.

The expected benefit per person is (1−p) × 0.69 + p × 0.000053. The total expected benefit across 10 people is 10 times this.

Evaluation at different values of p:

At p = 0 (no ASI), the benefit of AMF is 2.77 and the benefit of GD is 10 × 0.69 = 6.93. GD is roughly 2.5x more valuable than AMF.

At p = 0.5, the expected benefit of AMF is 0.5 × 2.77 + 0.5 × 12.15 = 7.46. The expected benefit of GD is 10 × (0.5 × 0.69 + 0.5 × 0.000053) = 3.47. AMF is roughly twice as valuable as GD.

At p = 1 (ASI certain), the benefit of AMF is 12.15 and the benefit of GD is 10 × 0.000053 = 0.00053. AMF is roughly 23,000x more valuable than GD.