Temporal discounting of gains and losses in monetary and health domains

Abstract

Delay discounting is the decrease in the subjective (present) value of a reward as a function
of the delay until its receipt. The delay discounting rates of money and health were
evaluated. We used a fixed sequence delay discount task, with four questionnaires of
hypothetical situations: monetary gains and losses, and health gains and losses (disease),
with five delays (1 month, 6 months, 1 year, 5 years and 10 years), and 20 binary options,
in ascending and descending order. Relative subjective value decreased as a function of
prospective time and the hyperbolic curve provided a good fit to the group data. A smaller
area under the curve (AUC) was observed in monetary domains compared to the health
domain with both signs and the AUC values were positively correlated in all conditions.
These results suggest that there was a sign effect both in the monetary and in health
domain, as well as domain independence. The reported data contribute to the growing
literature by showing the domain and sign effect on monetary and health domain through a
within-subject design and a fixed sequence task.