In theory, any ethical system that provides a total order over actions—basically, a relation that says “action A is better than action B”—is compatible with the “effective” part of effective altruism. The essence of effective altruism, then, is following a decision rule that says to choose the best action A available to you in any given situation.
As for the “altruism” part of EA, an ethical system would have to place value on “what’s good/right for others,” broadly defined. Usually that’s the well-being of other individuals (as in utilitarianism), but it could also be the health of the natural environment (as in environmentalism) or violating the rights of others as little as possible (as in deontology).
In theory, any ethical system that provides a total order over actions—basically, a relation that says “action A is better than action B”—is compatible with the “effective” part of effective altruism. The essence of effective altruism, then, is following a decision rule that says to choose the best action A available to you in any given situation.
As for the “altruism” part of EA, an ethical system would have to place value on “what’s good/right for others,” broadly defined. Usually that’s the well-being of other individuals (as in utilitarianism), but it could also be the health of the natural environment (as in environmentalism) or violating the rights of others as little as possible (as in deontology).