We examine the effect of raising the minimum legal sale age of tobacco to 21 (i.e., “T21”). We estimate difference-in-differences models using the Monitoring the Future (MTF) survey data and Nielsen Retail Scanner data from 2012 to 2019. Outcomes include cigarette and e-cigarette use and sales. We find sizable reductions in e-cigarette and cigarette use for 12th graders. T21 also reduced cigarette sales by 12.4 % and e-cigarette sales by 69.3 % in counties with the highest percent quartile of individuals under 21 years of age. In terms of mechanisms, we find that T21 increases ID checking and perceived risks of using both products.

中文翻译：

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估计烟草 21 对青少年烟草使用和销售的影响

我们研究了将烟草最低法定销售年龄提高至 21 岁（即“T21”）的影响。我们使用 2012 年至 2019 年监测未来 (MTF) 调查数据和尼尔森零售扫描仪数据来估计双重差分模型。结果包括卷烟和电子烟的使用和销售。我们发现 12 年级学生的电子烟和香烟使用量大幅减少。T21 还使 21 岁以下人口比例最高的县的卷烟销量减少了 12.4%，电子烟销量减少了 69.3%。在机制方面，我们发现T21增加了身份检查和使用这两种产品的感知风险。