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ERIC Number: EJ862939
Record Type: Journal
Publication Date: 2009-Nov
Pages: 22
Abstractor: As Provided
Reference Count: 35
ISSN: ISSN-0022-5002
Demand Equations for Qualitatively Different Foods under Fixed-Ratio Schedules: A Comparison of Three Data Conversions
Foster, T. Mary; Sumpter, Catherine E.; Temple, William; Flevill, Amanda; Poling, Alan
Journal of the Experimental Analysis of Behavior, v92 n3 p305-326 Nov 2009
Concurrent schedules were used to establish 6 hens' preferences for three foods. The resulting biases suggested wheat was preferred over honey-puffed and puffed wheat, and puffed wheat was the least preferred food. The hens then responded under fixed-ratio schedules for each food in 40-min (excluding reinforcer time) sessions, with the response requirement doubling each session until no reinforcers were received. At the smaller ratios, the less preferred the food, the faster the hens' overall response rates (mainly as a result of shorter postreinforcement pauses) and the more reinforcers they received. The relations between the logarithms of the number of reinforcers obtained (consumption) and the response ratio (price) were well fitted by curvilinear demand functions. Wheat produced the smallest initial consumption (ln "L"), followed by honey-puffed and puffed wheat, respectively. The response requirement at which the demand functions predicted maximal responding (P[subscript max]) were larger for wheat than for the other foods. Normalizing consumption and price, as suggested by Hursh and Winger (1995), moved the data for the three foods towards a single demand function; however, the P[subscript max] values were generally largest for puffed wheat. The results of normalization, as suggested by Hursh and Silberberg (2008), depended on the "k" value used. The parameter "k" is related to the range of the data, and the same "k" value needs to be used for all data sets that are compared. A "k" value of 8.0 gave significantly higher essential values (smaller [alpha] values) for puffed wheat as compared to honey-puffed wheat and wheat, and the P[subscript max] values, in normalized standard price units, were largest for puffed wheat. Normalizing demand by converting the puffed and honey-puffed wheat reinforcers to wheat equivalents (by applying the bias parameter from the concurrent-schedules procedure) maintained separate demand functions for the foods. Those for wheat had the smallest rates of change in elasticity (a, in contrast to the other analyses, the largest P[subscript max] values. Normalizing demand in terms of concurrent-schedule preference appears to have some advantages and to merit further investigation. (Contains 6 tables and 6 figures.)
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Publication Type: Journal Articles; Reports - Research
Education Level: N/A
Audience: N/A
Language: English
Sponsor: N/A
Authoring Institution: N/A