In many situations, individuals make decisions that involve both time and money consequences. For instance, a company that starts the development of a new product will spend both money and time with the hope of getting future financial benefits. Similarly, a student that decides to pursue a university degree accepts to invest time in the short term in order to get a higher salary in the long term. People also have to decide on a daily basis between future time-allocation plans in their private and professional lives: “Do I prefer to do a task now or postpone it for the future?”. Behavioral research has studied extensively the psychology of intertemporal discounting of money. However, despite the fact that time is a scarce and valuable resource, very few studies have analyzed the way people discount time.

The goal of our paper is therefore to understand whether people discount the value of time as they discount the value of money. We investigate this issue using a laboratory experiment where consequences are measured in units of money or in units of time and real incentives are implemented in gains and losses of time.

We observe significant differences between the discounting of time and the discounting of money. The paper also brings to light the complexity of time as compared with money and studies heterogeneity in discounting behaviors when outcomes are expressed in units of time.