Sumnall Harry R, Tyler Elizabeth, Wagstaff Graham F, Cole Jon C
Centre for Public Health, 8 Marybone, Liverpool John Moores University, Liverpool L3 2AP, UK.
Drug Alcohol Depend. 2004 Oct 5;76(1):93-9. doi: 10.1016/j.drugalcdep.2004.04.006.
Behavioural economic models of substance choice describe the relationship between changes in unit price and consumption. As the majority of UK non-dependent substance misusers are polysubstance misusers, we investigated the influence of price upon hypothetical purchases of alcohol, amphetamine, cocaine and ecstasy. Forty-three current polysubstance misusers (25 males, 18 females; mean age 21.3 +/- 2.8) were recruited into the study. As the price of alcohol rose, demand was inelastic. Amphetamine was a substitute for alcohol, cocaine was a compliment drug and ecstasy was independent. Demand for amphetamine was elastic as its price rose, but only alcohol was identified as a substitute drug and other drug purchases were independent of amphetamine price. As the price of cocaine increased, demand was elastic. Alcohol and ecstasy were substitute drugs but amphetamine purchase was independent, indicating asymmetrical substitution of alcohol and cocaine. Finally, demand for ecstasy was also elastic, but only cocaine substituted as ecstasy price rose. These results extend previous findings in substance dependent populations using behavioural economic models and support the opinion that purchasing substances is a complex process, involving both socio-economic and psychopharmacological factors. Whilst subjects expressed a preference for ecstasy, these behavioural findings indicated that alcohol was their drug of choice when economic considerations were brought into play. Self-reported drug preference, although facilitating between subjects experimental design, may therefore not accurately represent real world polysubstance misuse.
物质选择的行为经济学模型描述了单价变化与消费之间的关系。由于英国大多数非依赖型物质滥用者为多物质滥用者，我们调查了价格对酒精、安非他命、可卡因和摇头丸假设购买量的影响。43名当前的多物质滥用者（25名男性，18名女性；平均年龄21.3±2.8岁）被招募到该研究中。随着酒精价格上涨，需求缺乏弹性。安非他命是酒精的替代品，可卡因是互补性药物，摇头丸则与其他药物无关。随着安非他命价格上涨，其需求具有弹性，但只有酒精被确定为替代药物，其他药物的购买与安非他命价格无关。随着可卡因价格上涨，需求具有弹性。酒精和摇头丸是替代药物，但安非他命的购买与之无关，这表明酒精和可卡因的替代存在不对称性。最后，摇头丸的需求也具有弹性，但只有可卡因在摇头丸价格上涨时起到替代作用。这些结果扩展了先前使用行为经济学模型在物质依赖人群中的研究发现，并支持了购买物质是一个复杂过程的观点，该过程涉及社会经济和心理药理学因素。虽然受试者表示更喜欢摇头丸，但这些行为学发现表明，在考虑经济因素时，酒精是他们的首选药物。因此，自我报告的药物偏好虽然有助于进行受试者间的实验设计，但可能无法准确反映现实世界中的多物质滥用情况。
