Abstract
I consider whether a positive rate of pure intergenerational time preference is justifiable in terms of agent-relative moral reasons relating to partiality between generations, an idea I call discounting for kinship. I respond to Parfit's objections to discounting for kinship, but then highlight a number of apparent limitations of this approach. I show that these limitations largely fall away when we reflect on social discounting in the context of decisions that concern the global community as a whole.
Introduction
What costs do we think the current generation should be willing to bear for the sake of benefiting those that follow? Suppose, for simplicity, that we understand costs and benefits as changes in generalized consumption, taking this to include not only goods and services exchanged in the economy, but also non-market goods such as leisure, health, and environmental services. Under what circumstances is it desirable to reduce consumption in the current generation so as to increase consumption in future?
The aim of this paper is to help answer this question by considering whether a positive rate of pure intergenerational time preference is justifiable. Roughly speaking, this means that we care more about the welfare of people insofar as they are nearer to us in time. Broome (1994) notes that "[t]o many philosophers, this seems a reprehensible practice." (128) In this paper, I consider whether pure time preference is nonetheless justifiable on the basis of agent-relative moral reasons pertaining to partiality between generations. I argue that it is.
The next section explains the idea of a social discount rate on investment projects funded by reductions in current consumption. I set out and explain the Ramsey formula, and then proceed to characterize the controversy surrounding its parameters. I note the existence of broad agreement among moral philosophers that the rate of pure time preference should be zero. I suggest that this broad agreement may derive from neglecting relevant agent-relative reasons.
Section 3 discusses two objections raised against appealing to agent-relative reasons to justify a standard social discount rate, both due to Parfit (1984): firstly, that this approach provides no reason for discounting grave harms; and, secondly, that it requires the rate of pure time preference to decline with time. Responding to each point in turn, I argue that Parfit fails to provide a convincing argument against pure time discounting on the basis of declining bonds of partiality.
In Section 4, I outline three further observations about the limits of agent-relative discounting. Each observation turns, in some way or other, on the fact that any bonds of partiality that diminish with time apparently link us to only a proper subset of all people. Others, to whom we have no significant ties, cannot be said to be less important to us depending on their location in time. This seems to impose important limitations on the significance of agent-relative discounting.
However, in Section 5, I suggest that these limitations may be null when we reflect on cases like global climate change, where the decisions at issue seem to concern the global community as a whole. I outline the idea of collective reasons of partiality shared by the whole of currently existing humanity — an idea I call global collectivism — and consider whether and to what extent thinking in these terms allows us to circumvent the limits on agent-relative pure time discounting outlined in Section 4. I argue that they do so to a large extent.
In Section 6, I reflect on the conclusions arising from my discussion in Sections 4 and 5. I consider the possibility that there may exist other special relationships besides those involving family relatedness in light of which pure time discounting may be justified. I also consider whether discounting on the basis of declining relatedness is obligatory or merely permissible. Finally, I reflect on what such pure time discounting as is justified in terms of declining family relatedness tells us about the sacrifices to be made by the current generation on behalf of our descendants.
