Time Discounting for Primary and Monetary Rewards, Economic Letters
This paper shows that there is a positive and statistically significant correlation between the short-term discount rate over a monetary reward and the short-term discount rate over a primary reward (chocolate). In particular, for subjects who like chocolate and are hungry. This suggests that monetary rewards are suitable for the study of inter-temporal choice. In fact, given the problems associated with the use of primary rewards (differing tastes for the good, hunger, and possible satiation), we argue that measurement with monetary rewards is more reliable.
Ernesto G. Reuben, Paola Sapienza, Luigi Zingales
Reuben, G. Ernesto, Paola Sapienza, and Luigi Zingales. 2010. Time Discounting for Primary and Monetary Rewards. Economic Letters. 106: 125-127.