Temporal Discounting of Various Gift Cards Kathryn R. Glodowski, Rochelle R. Smits, & Daniel D. Holt Psychology Department, University of Wisconsin-Eau Claire Past research demonstrates that consumable rewards are discounted similarly to each other, yet different from money, a generalized conditioned reinforcer (Estle et al., 2007). The difference in discounting may be due to characteristic differences between consumable outcomes and money; consumable outcomes are immediately consumable whereas monetary outcomes are fungible. The current study sought to examine the controlling variables of discounting for a different conditioned reinforcer (gift card) for three qualitatively different outcomes (money, clothing, food). In sum, the results demonstrate that gift cards are discounted, and specifically the smaller amounts are discounted more steeply than the larger amounts, in accordance with previous research (Green, Myerson, & McFadden, 1997). These results extend the existing literature on temporal discounting because research has not yet examined conditioned reinforcers other than money. Results also portray all three gift card types are discounted similarly to one another at both the small and large amounts. These results suggest the controlling variable in discounting to be the characteristic of fungibility. This is especially apparent when comparing discounting of the money gift card and food gift card. Past research has found food to be discounted more steeply than money, but when the current study added fungible characteristic to food, the two outcomes are discounted similarly. Future research should look further into the comparison between a consumable outcome and a more fungible outcome similar to the consumable outcome. Specifically, a study could examine the differences in discounting of food and a food gift card. This comparison would allow for a more direct examination between an equivalent consumable and fungible outcome. Past research demonstrates that consumable rewards are discounted similarly to each other, yet different from money, a generalized conditioned reinforcer (Estle et al., 2007). The difference in discounting may be due to characteristic differences between consumable outcomes and money; consumable outcomes are immediately consumable whereas monetary outcomes are fungible. The current study sought to examine the controlling variables of discounting for a different conditioned reinforcer (gift card) for three qualitatively different outcomes (money, clothing, food). In sum, the results demonstrate that gift cards are discounted, and specifically the smaller amounts are discounted more steeply than the larger amounts, in accordance with previous research (Green, Myerson, & McFadden, 1997). These results extend the existing literature on temporal discounting because research has not yet examined conditioned reinforcers other than money. Results also portray all three gift card types are discounted similarly to one another at both the small and large amounts. These results suggest the controlling variable in discounting to be the characteristic of fungibility. This is especially apparent when comparing discounting of the money gift card and food gift card. Past research has found food to be discounted more steeply than money, but when the current study added fungible characteristic to food, the two outcomes are discounted similarly. Future research should look further into the comparison between a consumable outcome and a more fungible outcome similar to the consumable outcome. Specifically, a study could examine the differences in discounting of food and a food gift card. This comparison would allow for a more direct examination between an equivalent consumable and fungible outcome. We would like to thank UWEC’s Office of Research and Sponsored Programs for supporting this research. Introduction Method Individuals must make a vast amount of decisions every single day (e.g. what to wear, what to eat, what to do). Decisions are predictable when the alternatives differ in a single dimension (i.e. work for a job that has a large salary vs. a small salary). However, choices often involve outcomes that differ in multiple dimensions such as amount and delay (e.g. work a low-paying job right out of high school or receive a higher education for a higher-paying job in a few years). Previous research has found that instituting a delay to receiving a reward systematically decreases the subjective value of the reward. This effect has been termed temporal, or delay, discounting (for a review see Green & Myerson, 2004). Researchers have examined the rate of temporal discounting of various outcomes, including consumable and non-consumable outcomes (Estle, Green, Myerson, & Holt, 2007; Odum & Rainaud, 2003). Results demonstrated a difference between the consumable outcomes (e.g. candy, soda, alcohol) and money, a non-consumable, generalized conditioned reinforcer. That is, as the delay to receiving the outcomes increased, the subjective value of the consumable outcomes decreased significantly faster than the monetary outcomes. It has been posited that the difference in rates of temporal discounting between money and consumable outcomes is due to the consumable nature of the goods, yet the difference remains in that money is fungible (can be exchanged for a wide variety of goods) whereas consumable rewards are not. Although several studies have examined how individuals discount various consumable outcomes, researchers have yet to compare various conditioned reinforcers (i.e. exchangeable for a variety of goods). The present study controls for the reinforcer type (using all conditioned reinforcers) in order to gain a greater understanding of rates of discounting of various outcomes (money, clothes, and food). The current study also extends previous research to include a non-consumable but non-conditioned outcome (clothes). Results Figure 1 shows the median subjective values as a function of delay to receipt for all three gift card types and both amounts. Figure 2 shows the participants’ median area under the curve for all gift card types at both amounts, with bars representing the standard error of the means. A 2x3 (Card Type x Amount) Repeated Measures ANOVA was conducted. There were no significant differences between gift card types with F(2,70) = 1.189, p =.310. There was a significant difference between amounts with F(1,70) = 3.344, p <.001., with smaller amounts discounted more steeply. There was no significant interaction between card type and amount with F(2,70) = 1.242, p = participants recruited from a Midwest university and community technical college completed an online decision-making task that was accessed from any computer. Each participant made decisions regarding three gift card types (money, clothing, and grocery) at five delays (1 week, 1 month, 6 months, 1 year, and 5 years) for two amounts ($20 and $1000). For each outcome type, participants were presented with two options: hypothetically obtaining a gift card now or a larger amount of the gift card after a delay. After each choice, the amount of the immediate outcome titrated based on the participant’s decision in order to elicit a change in preference. After four decisions an indifference point was reached, which served as an estimate of the immediate subjective value of the delayed gift card. Discussion