Discounting in judgments of delay and probability

Subjects drew lines proportional in length to their subjective valuation of various amounts of money, available immediately and certainly, relative to a standard amount ranging across groups from $1,000,000 to $10. They also drew lines proportional to their subjective valuation of standard amounts w ith delays ranging from 1 day to 50 years and with probabilities ranging fr om 1/10 to 1/10,000,000. Amounts of certain-immediate money equivalent (in terms of drawn line length) to delayed or probabilistic money were determin ed. The delay and probability discount functions thereby obtained were hype rbolic in form, rather than exponential, consistent with previous findings. Large money amounts were valued higher when they were delayed by a day tha n when available immediately. Steepness of delay discounting was not system atically related to standard money amount but probabilistic discounting was steeper for higher standard amounts than for lower amounts. Some of these results differ from those obtained with choice procedures. Possible reasons for the differences are discussed. Copyright (C) 2000 John Wiley & Sons, L td.