The concept of present value is a standard and uncontroversial staple of business economists. While there may be some legitimate debate over the choice of interest rate to be used in any application, the idea of present value is not seriously in debate. It may come as a surprise, therefore, to...

We show that observed choices in discounting experiments are consistent with roughly one-half of the subjects using exponential discounting and one-half using quasi-hyperbolic discounting. We characterize the latent data generating process using a mixture model which allows different subjects to...