Delay discounting refers to a person preferring immediate rewards to future benefits, even if the future benefit is much larger than the sum of the immediate rewards. In monetary terms, it is the source of “the time value of money.” Money received in the future is considered worth less than money in hand, so interest must be paid to induce people to save money rather than hold it or spend it. 

In financial terms, future money is “discounted” to arrive at a rate of interest large enough to encourage savings. An ability to forgo current spending to save for retirement shows a lower level of delay discounting than a person in a similar financial situation who chooses to spend all they have. This tendency to discount future rewards can be measured quite accurately.

Almost all the baseline research into delay discounting, also called temporal discounting, involves money, perhaps because there’s a huge amount of data readily available about people’s preferences between a reward in the future and a reward today. In a large review article for the Journal of the Experimental Analysis of Behavior, a team of researchers working with Amy Odum, Professor in the Department of Psychology at Utah State University, extracted the results from studies that included both monetary research and at least one other reward:

[W]e calculated a proportional discounting measure to describe the relative degree of delay discounting between monetary and nonmonetary outcomes across a common metric. The proportional discounting measure was the discounting measure for the nonmonetary outcome divided by the sum of the discounting measures from both the nonmonetary outcome and from the monetary outcome. Proportions less than 0.5 indicate that the nonmonetary outcome was discounted to a lesser degree than the monetary outcome, whereas proportions greater than 0.5 indicate that the nonmonetary outcome was discounted to a greater degree than the monetary outcome.

Here’s a list of the nonmonetary rewards that were included in research analyzed by Dr. Odum’s team:

• Cigarettes
• Health Improvement
• Books
• Food
• Music
• Crack Cocaine
• Heroin
• Sex
• Marijuana
• Alcohol
• Soda Pop
• Candy
• Entertainment
• Chocolate
• Video Game
• Voucher

The two main conclusions from the analysis are, first, that all nonmonetary outcomes are discounted more than monetary outcomes and, second, that people with high monetary discounting tend to have high nonmonetary discounting as well. A third observation is that people addicted to substances have a far steeper delay discount for that substance than for other rewarding substances. Cigarette smokers, for example, are willing to give up a lot in the future to get access to cigarettes in the present.

In explaining the value of their work on substance use disorders, the authors state:

Understanding steep discounting of nonmonetary outcomes is important. In attempts to change behavior, such as to help people overcome addiction, many of the rewards for changing behavior are delayed (e.g., better health after quitting smoking) and opposed by immediate punishers (e.g., anxiety, difficulty concentrating, insomnia, irritability.

A study of delay discounting with 216 heroin addicts found a significant connection between steep delay discounting and relapse. The measure used for delay discounting was a computerized test asking the participant to state a preference between two outcomes. The outcomes allow researchers to determine what lengthening the time to reward does to participant preferences.

The authors conclude that higher rates of delay discounting lead to high rates of relapse or dropout from heroin addiction programs. “People with substance abuse disorders have impulsive behaviors and often prefer immediate reward,” the authors conclude.

We’ll continue examining delay discounting, impulsivity, and reward sensitivity as they relate to other compulsive disorders this week at AddictionNews, including behavioral disorders such as gambling addiction and internet addiction. Stay tuned!

Written by Steve O’Keefe. First published March 19, 2024.

Sources:

“Delay discounting of different outcomes: Review and theory,” Journal of the Experimental Analysis of Behavior, March 2020.

“The Role of Impulsivity and Sensitivity to Reward in Dropout of Addiction Treatment in Heroin Addicts,” Addiction & Health, January 2021.

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