One thing that hasn’t been pointed out as far as I can see is that long-run effects can’t be easily studied in a controlled fashion the way the primary effects of GiveWell’s top interventions have been studied. Hence there are several factors that can diminish them: we may develop effective ways to counter the effects, for good or ill; the effects may become irrelevant, e.g., due to the extinction of the species that care about them; or, in the counterfactual case, the effects may’ve been caused anyway a little later. With every year, the probability that any of these occurs or would have occurred increases, something that researchers try to account for by applying different kinds of exponential discount rates. The significant uncertainty about flow-through effects today should probably further increase our uncertainty about them in the future. Hence, insofar as positive or negative flow-through effects only become significant in the far future, we should not expect them to dominate the primary effects.
This does not apply to more near-term flow-through effects. Here many more efforts at quantifying small aspects of them, like Kyle’s, will be valuable.
One thing that hasn’t been pointed out as far as I can see is that long-run effects can’t be easily studied in a controlled fashion the way the primary effects of GiveWell’s top interventions have been studied. Hence there are several factors that can diminish them: we may develop effective ways to counter the effects, for good or ill; the effects may become irrelevant, e.g., due to the extinction of the species that care about them; or, in the counterfactual case, the effects may’ve been caused anyway a little later. With every year, the probability that any of these occurs or would have occurred increases, something that researchers try to account for by applying different kinds of exponential discount rates. The significant uncertainty about flow-through effects today should probably further increase our uncertainty about them in the future. Hence, insofar as positive or negative flow-through effects only become significant in the far future, we should not expect them to dominate the primary effects.
This does not apply to more near-term flow-through effects. Here many more efforts at quantifying small aspects of them, like Kyle’s, will be valuable.