Running head: A COMPARISON OF DISCOUNTING PROCEDURES

Several experimental procedures (e.g., adjusting amount, adjusting delay) have been used to study the effect that changes in amount of and delay to a reward have on the reward’s subjective value. The present series of three experiments sought to test the implicit assumption that the underlying decision-making process (discounting) is identical regardless of the procedure used, and that all would converge on similar indifference points. For each of the experiments, participants were initially tested on one of the adjusting tasks (Adjusting Immediate Amount, Adjusting Delayed Amount, or Adjusting Delay) and returned a week later to complete each of the remaining adjusting tasks. The indifference points obtained from the initial adjusting task were used as the test parameters in the other two tasks. That is, when participants completed the other two adjusting tasks, the amounts and delays experienced were identical to those from the initial adjusting task. Since, in the other adjusting tasks, the participants experience the identical amounts and delays as the initial adjusting task, specific predictions, at the level of the individual, were possible. Participants in all three experiments also completed a fully randomized version of the initial choice task. The results confirmed that, regardless of the choice task used, subjective value decreased as the delay to that outcome increased. In addition, it was found that under the adjusting-delay and the adjusting-