RAND Corporation, Santa Monica, CA, USA.
Department of Criminology and Criminal Justice at the University of South Carolina, Columbia, SC, USA.
J Policy Anal Manage. 2015 Winter;34(1):7-31. doi: 10.1002/pam.21804.
This paper sheds light on previous inconsistencies identified in the literature regarding the relationship between medical marijuana laws (MMLs) and recreational marijuana use by closely examining the importance of policy dimensions (registration requirements, home cultivation, dispensaries) and the timing of when particular policy dimensions are enacted. Using data from our own legal analysis of state MMLs, we evaluate which features are associated with adult and youth recreational and heavy use by linking these policy variables to data from the Treatment Episode Data Set (TEDS) and National Longitudinal Survey of Youth (NLSY97). We employ differences-in-differences techniques, controlling for state and year fixed effects, allowing us to exploit within-state policy changes. We find that while simple dichotomous indicators of MML laws are not positively associated with marijuana use or abuse, such measures hide the positive influence legal dispensaries have on adult and youth use, particularly heavy use. Sensitivity analyses that help address issues of policy endogeneity and actual implementation of dispensaries support our main conclusion that not all MML laws are the same. Dimensions of these policies, in particular legal protection of dispensaries, can lead to greater recreational marijuana use and abuse among adults and those under the legal age of 21 relative to MMLs without this supply source.
本文通过仔细研究政策维度（注册要求、家庭种植、药房）和特定政策维度颁布时间的重要性，揭示了先前文献中关于医用大麻法规（MML）与娱乐性大麻使用之间关系的不一致之处。利用我们对州 MML 进行法律分析的数据，我们通过将这些政策变量与治疗期数据集中（TEDS）和全国青年纵向调查（NLSY97）的数据联系起来，评估哪些特征与成人和青年娱乐性和重度使用相关。我们采用差异中的差异技术，控制州和年份的固定效应，从而能够利用州内政策变化。我们发现，虽然 MML 法律的简单二分法指标与大麻使用或滥用没有正相关关系，但这些措施掩盖了合法药房对成人和青年使用，特别是重度使用的积极影响。有助于解决政策内生性和药房实际实施问题的敏感性分析支持我们的主要结论，即并非所有 MML 法律都是相同的。这些政策的维度，特别是对药房的法律保护，可以导致成年人和 21 岁以下的人比没有这种供应来源的 MML 更多地使用和滥用娱乐性大麻。
