Diacritica 25-2_Filosofia.indb - cehum - Universidade do Minho

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CÉDRIC RIO
we are not sure to have the possibility to obtain satisfaction in the future
because of our death, or because of the transformation of our preferences in
time. Individuals are supposed to choose a smaller satisfaction because of
such an uncertainty. At the opposite, some authors suggest that individuals
give their assent to a present pleasure solely because of its temporal position.
In other terms, individuals would prefer a present satisfaction solely
because it will arrive sooner: the same potential satisfaction would have
then more value in the present for individuals than in the future. [4]
A positive social discount rate illustrates then the fact that current generations’
well-being appears socially more relevant than future generations’
well-being. Economists recognize that social discount rate value result from
the addition of Elasticity of marginal utility and Time preference but they
disagree about the value to accord to both elements. Most of them defend
a positive elasticity of marginal utility and a Time preference equal to zero:
they defend a positive social discount rate because future generations are
supposed to be better-off than previous one. But some economists as Nordhaus
defend also a positive Time preference and argue that according to
consumer’s sovereignty, individual behaviour and his preference for the
present should be translated at a social level (Nordhaus, 2008). [5]
Liberal egalitarianism and temporal neutrality
Liberal egalitarians reject a positive social discount rate. Two arguments are
generally proposed against such a proposal. First of all, they consider that
the hypothesis of a positive social discount rate is ad hoc (Rawls, 1999; Gosseries,
2004). Th ey accuse Utilitarians to defend such a proposition only to
attenuate sacrifi cial tendency of their perspective. For Utilitarians, a good
social policy consists in maximizing the well-being of the society but they
do not care about the distribution of the well-being among individuals in
the society. And in an intergenerational context, if we assume that the social
discount rate is equal to zero, Utilitarianism could legitimate the sacrifi ce
of members of current generations in order to improve well-being of mem-
4 It is the main explication proposed by Eugen von Böhm-Bawerk and the marginalists to justify
the interest rate (See Böhm-Bawerk, 1930: 237).
5 Many authors, through Social choice theory or through a discussion about the moral obligation
to reproduce at a political or social level an individual behaviour, discuss the legitimacy of such
an argument but we will not reproduce it here. We will focus our discussion on Liberal reasons
to not assume a positive social discount rate. To have an overview of arguments against social
discount rate, see “Against social discount rate” (Cowen/Parfi t, 1992).
Diacritica 25-2_Filosofia.indb 54 05-01-2012 09:38:20