Aggregation and the Structure of Value

ABSTRACT Roughly, the view I call “Additivism” sums up value across time and people. Given some standard assumptions, I show that Additivism follows from two principles. The first says that how lives align in time cannot, in itself, matter. The second says, roughly, that a world cannot be better unless it is better within some period or another. These principles, while plausible, presuppose a rich underlying structure of value—presuppositions that are implicit in the standard numerical framework of population ethics but that are often overlooked. A careful exploration of Additivism and the case for it reveals intricate connections between substantive questions about what value fundamentally consists in and structural questions about how to aggregate value.