DeGrandpre R J, Bickel W K, Rizvi S A, Hughes J R
Department of Psychiatry, University of Vermont, Burlington 05401-1419.
J Exp Anal Behav. 1993 May;59(3):483-500. doi: 10.1901/jeab.1993.59-483.
The effects of income (money available to spend during the experimental session) on human choice were examined in a concurrent-schedule arrangement. Subjects were 7 nicotine-dependent smokers, and reinforcers were puffs on the subject's usual brand of cigarette ("own") and puffs on a less preferred brand of cigarette with equal nicotine content ("other"). Across sessions, income varied and the price of the two reinforcers was held constant, with the other puffs one fifth the price of the own puffs. As income increased, consumption of own puffs increased while consumption of the less expensive other puffs decreased. These effects of income on choice were highly consistent across subjects. For some subjects, however, income had little effect on total puff consumption. Finally, an additional condition examined whether price and income manipulations would have functionally equivalent effects on choice by repeating an income condition in which the price of the other brand was increased. Although the increased price of the other puffs decreased their consumption in 4 subjects, 2 subjects showed increased consumption of the other puffs at the higher price. The results, when defined in economic terms, indicate that the own puffs were a normal good (consumption and income are directly related), the other puffs were an inferior good (consumption and income are inversely related), and the direct relationship between consumption of the other puffs and their price is defined as a Giffengood effect. The latter result also suggests that for these 2 subjects, price and income manipulations had equivalent effects on choice. These results extend findings from previous studies that have examined the effects of income on choice responding to human subjects and drug reinforcers, and provide a framework for further experimental tests of the effects of income on human choice behavior. Methodological and theoretical implications for the study of choice and for behavioral pharmacology are discussed.
在一个并发式安排中，研究了收入（实验期间可用于支出的金钱）对人类选择的影响。受试者为7名尼古丁依赖吸烟者，强化物是受试者常用品牌香烟的抽吸次数（“自己的”）以及同等尼古丁含量但较不喜欢品牌香烟的抽吸次数（“其他的”）。在各个实验阶段，收入有所变化，两种强化物的价格保持不变，其他抽吸次数的价格是自己抽吸次数价格的五分之一。随着收入增加，自己抽吸次数的消费量增加，而较便宜的其他抽吸次数的消费量减少。收入对选择的这些影响在受试者中高度一致。然而，对于一些受试者来说，收入对总抽吸量影响很小。最后，一个额外的条件通过重复其他品牌价格提高的收入条件，研究了价格和收入操纵对选择是否会产生功能上等效的影响。尽管其他抽吸次数价格的提高使4名受试者的消费量减少，但有2名受试者在较高价格下其他抽吸次数的消费量增加。从经济角度定义，结果表明自己的抽吸次数是正常商品（消费与收入直接相关），其他抽吸次数是劣等商品（消费与收入呈负相关），其他抽吸次数的消费与其价格之间的直接关系被定义为吉芬商品效应。后一结果还表明，对于这2名受试者，价格和收入操纵对选择产生了等效影响。这些结果扩展了先前研究的发现，这些研究考察了收入对人类受试者选择反应和药物强化物的影响，并为进一步实验测试收入对人类选择行为的影响提供了框架。讨论了对选择研究和行为药理学的方法学及理论意义。
