Decomposing the social discount rate

Recent modelling of the costs and benefits of climate change has renewed debate surrounding assumptions regarding the social discount rate in analysing the impacts of environmental change. Previous literature segments the social discount rate into being influenced by two key factors; the rate of pure time preference and the elasticity of marginal utility of future consumption. These components of the social discount rate reinforce the linkages between the choice of social discount rate and intergenerational distribution. In an extension of previous work by the author on intergenerational distributional preferences, this paper discusses the relationship between intergenerational equity and the social discount rate. The work has significant policy implications given the sensitivity of Cost Benefit Analysis outcomes to assumptions regarding the social discount rate.