Labor Supply and Consumption of Food in a Closed Economy Under a Range of Fixed- And Random-Ratio Schedules: Tests of Unit Price

Abstract

The behavioral economic concept of unit price predicts that consumption and response output (labor supply) are determined by the unit price at which a good is available regardless of the value of the cost and benefit components of the unit price ratio. Experiment 1 assessed 4 pigeons' consumption and response output at a range of unit prices. In one condition, food was available according to a range of fixed-ratio schedules, whereas in the other condition, food was available according to a range of random-ratio schedules. Consistent with unit price predictions, consumption and response output were approximately equivalent across schedule types within the lower range of unit prices. However, at Unit Prices 64 (ratio value ϭ 192) and greater, considerably more consumption and response output were observed in the random-ratio condition. Experiment 2 replicated these findings with 4 pigeons using the rapid demand curve assay procedure that is commonly used in the behavioral economics literature. Findings are integrated with two mathematical models of behavior under variable reinforcer delays.

Random-ratio schedules produce greater demand for i.v. drug administration than fixed-ratio schedules in rhesus monkeys

“…The finding that RR schedules generate greater drug demand at high unit prices expands and generalizes similar results reported byMadden et al (2005). These investigators used food as a reinforcer in pigeon subjects that were responding under closed-economic conditions (i.e., their entire daily food intake was earned during experimental sessions).…”

“…Since it has been readily established that reinforcers lose their value hyperbolically when delayed in the future (e.g., Mazur, 1984), those reinforcers that are delivered after few responses in a variable schedule have considerably more value than those that are delivered after many responses (even when the average payoff is held constant). This hyperbolic discounting of delayed outcomes could account for how the same drugs can maintain higher response rates and higher essential value when delivered after a random number of responses Madden et al (2005). extended this analysis and suggested that unit price (when used in obtaining demand functions) may be appropriately modified by dividing it by the value of the reinforcer as obtained by the hyperbolic discounting function (Mazur 1984).…”

“…extended this analysis and suggested that unit price (when used in obtaining demand functions) may be appropriately modified by dividing it by the value of the reinforcer as obtained by the hyperbolic discounting function (Mazur 1984). When Madden et al (2005) calculated their demand curves using this measure of price, the difference between consumption under variable and fixed schedules disappeared.…”

“…Other studies with similar aims have examined free-operant responding when only one schedule type is available. For example,Madden et al (2005) demonstrated that pigeons responding for food under closed-economic conditions respond at higher rates and consume more food when reinforcers are delivered according to a random ratio (RR) as compared with fixed ratio (FR) schedules, particularly at high unit prices - a quantified relation between work ratio and payoff amount.…”

An Inexpensive Infrared Detector to Verify the Delivery of Food Pellets

“…In the course of examining an animal's behavior in an appetitive environment, it is crucial for the experimenter to control the amount and availability of food. In some of our research in choice and behavioral economics, for example, having exact control over food delivery is paramount because the specific ratios between responses and food amounts are the primary independent variables (e.g., Hursh et al, 1988;Madden, Dake, Mauel, & Rowe, 2005). Most behavioral researchers have a story, usually several, about how an apparatus failure resulted in the loss of data, disruption of a stable baseline performance, interruption of a dosing regimen, etc.…”