Discounting of delayed hypothetical money and food: Effects of amount

Delay discounting research determines how the value of an outcome is affected by delay to its receipt. Research so far shows that consumable outcomes are discounted more steeply by delay than money. Prior studies, however, have used large amounts of the outcomes (e.g. $100 worth) that would not typically be consumed in one bout, unlike the corresponding amount of money (e.g. $100). This experiment examined whether small amounts of food would be discounted more steeply than money, as occurs with larger amounts. One hundred and two adults indicated their preferences in a series of choices for two hypothetical outcome types: immediate versus delayed food and immediate versus delayed money. Participants made choices involving either relatively small maximum amounts of food ($10 worth) and money ($10) or for relatively large maximum amounts of food ($100 worth) and money ($100). In the within-subject comparisons, food was discounted more steeply by delay than money for both groups. In the between-subject comparisons, different amounts of the commodities were affected similarly by delay. Overall, these results suggest that steeper discounting of consumable outcomes than money is a fairly robust phenomenon, occurring with relatively small amounts of outcomes as well as with larger amounts.