UNIT PRICE AS A USEFUL METRIC IN ANALYZING EFFECTS OF REINFORCER MAGNITUDE

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.