Doyle's (2013) theoretical survey of discount functions criticizes two parametric families abbreviated as CRDI and CADI families. We show that Doyle's criticisms are based on a mathematical mistake and are incorrect.

Constant relative decreasing impatience, Hyperbolic discounting, Intertemporal choice
Judgment and Decision Making
Erasmus School of Economics

Bleichrodt, H, Potter van Loon, R.J.D, Rohde, K.I.M, & Wakker, P.P. (2013). A criticism of Doyle's survey of time preference: A correction regarding the CRDI and CADI families. Judgment and Decision Making, 8(5), 630–631. Retrieved from