Discounting of delayed and probabilistic rewards was examined in two relatively large samples (Ns > 100). For both types of rewards, a hyperbola-like discounting function provided good fits to individual data. Amount of reward had opposite effects on temporal and probability discounting: Smaller delayed rewards were discounted more steeply than larger delayed rewards, whereas larger probabilist...

Assessment of climate change policies requires aggregation of costs and benefits over time and across generations, a process ordinarily done through discounting. Choosing the correct discount rate has proved to be controversial and highly consequential. To clarify past analysis and guide future work, we decompose discounting along two dimensions. First, we distinguish discounting by individuals...

In recent decades, researchers have integrated measurements of delay discounting, how the subjective valuation of a reward changes as a function of time, into their study of addiction. Research has begun to explore the idea that delay discounting may serve as both a marker for the effectiveness of existing treatments for addiction and a potential target for novel intervention strategies. As thi...

Observed animal impulsiveness challenges ideas from foraging theory about the fitness value of food rewards, and may play a role in important behavioural phenomena such as cooperation and addiction. Behavioural ecologists usually invoke temporal discounting to explain the evolution of animal impulsiveness. According to the discounting hypothesis, delay reduces the fitness value of the delayed f...

Negative symptoms in schizophrenia have been grouped into the 2 factors of apathy and diminished expression, which might be caused by separable pathophysiological mechanisms. Recently, it has been proposed that apathy could be due to dysfunctional integration of reward and effort during decision making. We asked whether apathy in particular is associated with stronger devaluation ("discounting"...

Foraging decisions in nonhuman animals often require choosing between small, immediate food rewards and larger, more delayed rewards. Faced with such choices, animals typically discount or devalue the future quite strongly. Although discounting studies often focus on delays to reward access, other temporal intervals contribute to foraging rate, and thus may potentially influence discounting lev...

Ten dollars today is more attractive than the same amount of money tomorrow and is consistent with the well known proverb, “a bird in the hand is worth two in the bush.” We all know that the value of a reward is discounted over time. How the value discounts over time and what is the rationale for such discounting, however, is less clear. Classical economic theory has assumed an exponential form...

OBJECTIVE We investigated the relationship between impulsivity, as measured by delay and probability discounting, and gambling-related cognitions and behavior in adults with and without ADHD. METHOD Adults who met Diagnostic and Statistical Manual of Mental Disorders (4th ed.; DSM-IV) diagnostic criteria for ADHD (n = 31) and controls (n = 29) were recruited from the community. All completed ...

The present study demonstrated the relative impact of gambling and nongambling contexts on the degree of delay discounting by pathological gamblers. We used a delay-discounting task with 20 pathological gamblers in and out of the natural context in which they regularly gambled. For 16 of the 20 participants, it appeared that the difference of context altered the subjective value of delayed rewa...

Background: Space-Time Discounting Discounting is typically defined as the process of comparing the values of costs and benefits that occur at different times. This definition neglects where costs and benefits occur. For example, we might discount future costs and benefits because we care less about the welfare of people in the future, but we might also discount the welfare of people in differe...