Individual differences in degree of discounting: Do different procedures and measures assess the same construct?

Area of Science:

• Behavioral Economics
• Decision Science

Background:

• Delay discounting quantifies the reduction in the value of a reward as a function of the delay to its receipt.
• The Adjusting-Amount procedure and the Monetary Choice Questionnaire (MCQ) are prominent methods for assessing delay discounting.

Purpose of the Study:

• To determine if the Adjusting-Amount procedure and the MCQ measure the same underlying construct of delay discounting.
• To compare the efficacy of these two prominent delay discounting measurement procedures.

Main Methods:

• Two online samples (N=150 and N=243) were recruited via Prolific and MTurk platforms.
• Participants completed both the Adjusting-Amount procedure and the MCQ to measure delay discounting.
• Analyses examined correlations between the two procedures across different reward amounts and theoretical/atheoretical measures.

Main Results:

• Both the Adjusting-Amount procedure and the MCQ produced generally similar results.
• High correlations were observed between the degree of discounting measured by both procedures.
• This consistency held regardless of the sample, reward amount, or specific discounting metric used (log k, area under the curve, or proportion of delayed choices).

Conclusions:

• The Adjusting-Amount procedure and the MCQ are highly correlated, suggesting they assess the same construct of delay discounting.
• These findings support the use of either procedure for measuring delay discounting in behavioral economic research.
• The robustness of the correlation across various parameters enhances confidence in the validity of both measurement tools.