Effort- and time-cost effects on demand curves for food by pigeons under short session closed economies

• Published in: Behavioural processes 2001-03, Vol.53 (1), p.47-56
• Main Author: Tsunematsu, Shin
• Format: Article
• Language: English
• Subjects: Animal; Behavioral economics; Biological and medical sciences; Conditioning; Cost; Demand curves; Fundamental and applied biological sciences. Psychology; Key peck; Learning. Memory; Pigeons; Psychology. Psychoanalysis. Psychiatry; Psychology. Psychophysiology; Session length
• ISSN: 0376-6357; 1872-8308
• DOI: 10.1016/S0376-6357(00)00147-9

Demand curves for food were compared under the effort- and time-cost conditions using response-initiated fixed-ratio (FR) and fixed-interval (FI) schedules. For the effort-cost conditions, two pigeons were exposed to FR 3, 30, 90, and 150 for six sessions each. The time equivalent of each ratio was a FI schedule, each FI value equal to an average time from the first peck on the ratio to reinforcement (3-s access to mixed grain). The experiment was repeated in 1.5-, 3.0-, and 4.5-h closed economies in a different order for each pigeon. Food consumption as a function of time-based unit price (time equivalent per reinforcement duration) for each session length showed moderate convergence on a single demand function for the two cost conditions. When the demand function was separately fitted to each cost condition, however, the ranges of inelastic demand were generally larger in time-cost than effort-cost conditions. These curve-fitting analyses suggest that although time is a critical cost factor decreasing consumption at moderate prices, food intake under the effort-cost condition decreases more rapidly than under the time-cost condition as unit price increases. The analyses provide useful descriptions for the functional difference of costs.