Rj. Degrandpre et al., UNIT PRICE AS A USEFUL METRIC IN ANALYZING EFFECTS OF REINFORCER MAGNITUDE, Journal of the experimental analysis of behavior, 60(3), 1993, pp. 641-666
In this paper, we applied the behavioral-economic concept of unit pric
e to the study of reinforcer magnitude in an attempt to provide a cons
istent account of the effects of reinforcer magnitude on behavior. Rec
ent research in the experimental analysis of behavior and in behaviora
l pharmacology suggests that reinforcer magnitude interacts with the s
chedule of reinforcement to determine response rate and total consumpt
ion. The utility of the unit-price concept thus stems from its ability
to quantify this interaction as a cost-benefit ratio (i.e., unit pric
e = characteristics of the schedule of reinforcement divided by magnit
ude of reinforcement). Research employing the unit-price concept has s
hown that as unit price increases, a positively decelerating function
exists for consumption (i.e., a function with an increasingly negative
slope, when plotted on log coordinates) and a bitonic function exists
for response rate. Based on these findings, the present analysis appl
ied the unit-price concept to those studies of reinforcer magnitude an
d drug self-administration that examined the effects of reinforcer mag
nitude on response rate using simple schedules of reinforcement (e.g.,
fixed-ratio schedule). This resulted in three findings: (a) Reinforce
r-magnitude manipulations and schedule manipulations interact in a man
ner that can be quantified in terms of unit price as benefit and cost
factors, respectively; (b) different reinforcer-magnitude manipulation
s are functionally interchangeable as benefit factors in the unit-pric
e ratio; and (c) these conclusions appear warranted despite difference
s in reinforcers (food or drug), species (dogs, monkeys, or rats), and
schedules (interval or ratio), and despite the fact that these studie
s were not designed for a unit-price analysis. In methodological terms
, these results provide further evidence that employing the unit-price
concept is a parsimonious method for examining the effects of reinfor
cer magnitude. In theoretical terms, these results suggest that a sing
le process may underlie the effect of combined reinforcer-magnitude an
d schedule manipulations.