It isn’t sufficient in my view merely that a positive EV action exists, you also need to be able to identity at least one such action, or else you are in the situation where longtermism is only theoretical and doesn’t actually recommend certain actions. This makes the difficulty of modeling the future more of an issue that your post suggests because in realistic situations you need to estimate these EVs, you don’t just know them.
The relevant uncertainty is in the estimated EV of a specific actions or intervention, it isn’t sufficient for your argument merely to know that positive EV actions exists, or even that one is in some class of interventions (like those that plausibly reduce extinction risk), for longtermism to suggest a specific action is good. It requires considering the EV of that specific action, estimation error included. The difficulty of performing that estimation is therefore a difficulty for longtermism.
It isn’t sufficient in my view merely that a positive EV action exists, you also need to be able to identity at least one such action, or else you are in the situation where longtermism is only theoretical and doesn’t actually recommend certain actions. This makes the difficulty of modeling the future more of an issue that your post suggests because in realistic situations you need to estimate these EVs, you don’t just know them.
The relevant uncertainty is in the estimated EV of a specific actions or intervention, it isn’t sufficient for your argument merely to know that positive EV actions exists, or even that one is in some class of interventions (like those that plausibly reduce extinction risk), for longtermism to suggest a specific action is good. It requires considering the EV of that specific action, estimation error included. The difficulty of performing that estimation is therefore a difficulty for longtermism.