Discounting in the Economics of Climate Change

It was frequently argued that the discount rate is the most important single figure in the economics of climate change. Due to this figure we observe large differences in policy recommendation between different economists of climate change (most notably, the choice of the discount rate determines the difference in what William Nordhaus on the one hand, and Nicholas Stern, on the other, call for). There is no concrete recommendation in standard economics how to discount long run benefits and losses. But it is clear that, if you want to compare benefits from the future with costs today, you need a discount rate. So far agreement prevails. The problem is the definition (or: choice) of the “right” discount rate, which involves economic forecasts as well as ethical decisions. In the following I shall present an overview about the main arguments in the discussion. Continue reading