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 with delays ranging from 1 day to 50 years and with probabilities ranging from 1/10 to 1/10,000,000. Amounts of certain‐immediate moneyequivalent (in terms of drawn line length) to delayed or probabilistic money were determined. The delay and probability discount functions thereby obtained were hyperbolic in form, rather than exponential, consistent with previous findings. Large money amounts were valued higherwhentheyweredelayedbyadaythanwhenavailableimmediately.Steepness of delay discounting was not systematically related to standard money amount but probabilistic discounting was steeper for higher standard amounts than for lower amounts. Some of these results diAer from those obtained with choice procedures. Possible reasons for the diAerences are discussed. Copyright #2000 John Wiley & Sons, Ltd.