Discounting in economic evaluations

Appropriate discounting rules in economic evaluations have received considerable attention in the literature and in national guidelines for economic evaluations. Rightfully so, as discounting can be quite influential on the outcomes of economic evaluations. The most prominent controversies regarding discounting involve the basis for and height of the discount rate, whether costs and effects should be discounted at the same rate, and whether discount rates should decline or stay constant over time. Moreover, the choice for discount rules depends on the decision context one adopts as the most relevant. In this article, we review these issues and debates, and describe and discuss the current discounting recommendations of the countries publishing their national guidelines. We finish the article by proposing a research agenda.