The purpose of the project was to develop the Discounting Inventory (DI), a measure of individual differences in delay, probability,
effort, and social discounting, all related to behavioral impulsivity. Over 400 items relating to four types of discounting were generated.
Next, a study followed by a series of psychometric analyses of data obtained from a group of 2843 individuals was conducted. Principal
Component Analysis yielded a four-factor structure of data, reflecting the four types of discounting. The results of Confirmatory Factor
Analysis showed good fit of the four-factor model to data. Through several iterations of retaining and deleting items on the basis of their
component loadings, item intercorrelations, and contribution to coefficient alphas, the total number of items was reduced to 48. The
final 48-item version of the inventory has satisfactory psychometric characteristics, including Cronbach’s alpha and test–retest stability.
In addition, significant correlations were observed between the DI and traditional discounting instruments, suggesting that the DI
measures a construct similar to the behavioral discounting process. The development of the tool was based on the assumption that
discounting is a personality trait. However, the present data suggest that discounting may reflect more a state than trait function.

EB00000003192K

Available

• Assessing individual differences in discounting: Construction and initial validation of the Discounting Inventory