Dr. Jonathan Friedel: Experimental Tests of the Additive Utility Model of Delay Discounting

Abstract

Delay discounting describes the process of how delayed outcomes lose value. The additive utility model of delay discounting (Killeen, 2015) explains delay discounting as a process of utilities. Utility is gained by receiving some outcome and utility is lost by waiting for that outcome. Across several studies, the parameters of the additive utility model were determined through traditional utility function. The additive utility model (with the predetermined parameters) was then used to predict indifference points in delay discounting tasks. Comparisons in fit quality will be made between the additive utility model and the hyperbolic discounting model (Mazur, 1987). The additive utility model tends to perform as well as the hyperbolic model, though the additive utility model may have some quantitative limitations. The additive utility model is more robust as a theoretical account of discounting, but may be complex at best or nonviable at worst for subject-level explanations.