Petry N M, Bickel W K
Substance Abuse Treatment Center, University of Vermont, Burlington, USA.
Addiction. 1998 Mar;93(3):321-35. doi: 10.1046/j.1360-0443.1998.9333212.x.
To assess how price and income affect hypothetical drug-purchasing decisions of polydrug abusers undergoing treatment for heroin addiction.
PARTICIPANTS, DESIGN AND SETTING: Forty subjects participated in experiments in which they hypothetically "purchased" drugs as price or income varied.
Experiment 1 examined effects of heroin price on purchases of heroin, valium, cocaine, marijuana and alcohol. Experiment 2 examined the effects of both heroin and valium prices on purchases of these drugs. In both these experiments, income remained constant. Experiment 3 examined the effects of increasing income on drug choices, with drug prices constant.
As price of heroin rose in Experiment 1, heroin purchases decreased. Reductions in heroin purchases were proportionally less than price increases, demonstrating inelastic demand for heroin. Valium and cocaine purchases increased as heroin price rose, and cross-price elasticity coefficients indicated that these drugs substituted for heroin. In Experiment 2, demand for both heroin and valium was inelastic. Valium substituted for heroin, but heroin purchases were independent of valium prices, suggesting an asymmetrical substitution effect. Marijuana and alcohol purchases were independent of valium price, but both these drugs substituted for heroin. In Experiment 3 demand for heroin and cocaine was income elastic, with purchases rising in greater proportion than income. Marijuana, alcohol and valium purchases did not vary with income, demonstrating that demand for these drugs was income inelastic. Hypothetical choices were reliable both between and within subjects. Moreover, drug choices in this hypothetical situation were correlated with urinalysis results, demonstrating initial validity of this methodology.
This methodology may be useful for understanding the phenomenon of polydrug abuse.
评估价格和收入如何影响正在接受海洛因成瘾治疗的多药滥用者在假设情况下的购药决策。
参与者、设计与地点：40名受试者参与了实验，在实验中他们在价格或收入变化时假设性地“购买”药物。
实验1研究海洛因价格对海洛因、安定、可卡因、大麻和酒精购买量的影响。实验2研究海洛因和安定价格对这些药物购买量的影响。在这两个实验中，收入保持不变。实验3研究收入增加对药物选择的影响，此时药物价格保持不变。
在实验1中，随着海洛因价格上涨，海洛因购买量减少。海洛因购买量的减少比例小于价格上涨比例，表明海洛因需求缺乏弹性。随着海洛因价格上涨，安定和可卡因的购买量增加，交叉价格弹性系数表明这些药物可替代海洛因。在实验2中，海洛因和安定的需求均缺乏弹性。安定可替代海洛因，但海洛因购买量与安定价格无关，表明存在不对称替代效应。大麻和酒精的购买量与安定价格无关，但这两种药物均可替代海洛因。在实验3中，海洛因和可卡因的需求富有收入弹性，购买量增长比例大于收入增长比例。大麻、酒精和安定的购买量不随收入变化，表明这些药物的需求缺乏收入弹性。假设性选择在受试者之间和受试者内部都是可靠的。此外，这种假设情况下的药物选择与尿液分析结果相关，证明了该方法的初步有效性。
这种方法可能有助于理解多药滥用现象。
