Behavioural Economics: The Inferior-Good Effect
type: CreativeWork
description: These experiments used 15 domestic hens to investigate the inferior-good effect, a decrease in consumption of a commodity as income increases. Experiment 1 investigated plain and salted wheat to serve as superior goods (opposite to inferior goods) and inferior goods. Hens consumed mostly plain wheat when given ad-libitum access so it was the intended superior good and salted wheat was the intended inferior good. In the next experiments, 3 s of plain wheat and 10 s of salted wheat were available for single responses on 2 keys during discrete trials. Income changed by changing the inter-trial interval (ITI) of fixed-length sessions or the total number of trials. Experiment 2 partially replicated the Silberberg et al. (1987) procedure, using the ITI income analogue for 6 hens. When income increased, 4 hens sometimes responded less on the salted-wheat key (demonstrating the inferior-good effect), 2 of these hens and a 5th hen sometimes responded more on both keys but proportionally more on the plain-wheat key (termed here as a relative inferior-good effect). Experiment 3a partially replicated the Hastjarjo et al. (1990a) procedure using the total-trials analogue for 7 other hens. The inferior-good effect occurred across some conditions for 2 hens while other hens tended to respond on the plain-wheat key, suggesting lack of contingency contact. When a 60-s ITI was added in Experiment 3b, variability increased for most hens, but only 1 hen showed the effect, 1 of the hens that did so in Experiment 3b. These 6 hens' (1 died) 80% bodyweights were re-assessed in Experiment 4 and hens were below 80% during Experiments 3a and 3b, suggesting that the lack of the inferior-good effect was not due to some hens being at high weights. The ITI analogue was used for these 6 hens in Experiment 5 and the effect occurred for 2 hens. Experiment 6 added forced-choice trials to the total-trials analogue (with 60-s ITI) to guarantee contingency contact. The inferior- and/or relative-inferior…
abstract: These experiments used 15 domestic hens to investigate the inferior-good effect, a decrease in consumption of a commodity as income increases. Experiment 1 investigated plain and salted wheat to serve as superior goods (opposite to inferior goods) and inferior goods. Hens consumed mostly plain wheat when given ad-libitum access so it was the intended superior good and salted wheat was the intended inferior good. In the next experiments, 3 s of plain wheat and 10 s of salted wheat were available for single responses on 2 keys during discrete trials. Income changed by changing the inter-trial interval (ITI) of fixed-length sessions or the total number of trials. Experiment 2 partially replicated the Silberberg et al. (1987) procedure, using the ITI income analogue for 6 hens. When income increased, 4 hens sometimes responded less on the salted-wheat key (demonstrating the inferior-good effect), 2 of these hens and a 5th hen sometimes responded more on both keys but proportionally more on the plain-wheat key (termed here as a relative inferior-good effect). Experiment 3a partially replicated the Hastjarjo et al. (1990a) procedure using the total-trials analogue for 7 other hens. The inferior-good effect occurred across some conditions for 2 hens while other hens tended to respond on the plain-wheat key, suggesting lack of contingency contact. When a 60-s ITI was added in Experiment 3b, variability increased for most hens, but only 1 hen showed the effect, 1 of the hens that did so in Experiment 3b. These 6 hens' (1 died) 80% bodyweights were re-assessed in Experiment 4 and hens were below 80% during Experiments 3a and 3b, suggesting that the lack of the inferior-good effect was not due to some hens being at high weights. The ITI analogue was used for these 6 hens in Experiment 5 and the effect occurred for 2 hens. Experiment 6 added forced-choice trials to the total-trials analogue (with 60-s ITI) to guarantee contingency contact. The inferior- and/or relative-inferior…
author: Messick, Eric Michael
keywords: behavioural economics, inferior good, income, choice, consumption, body weight, crop, gallus domesticus
date published: 2007
date modified: 2026-07-24T05:57:15Z
provider: University Waikato
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: The University of Waikato