中文摘要
美国的肥胖率已上升至流行病级别。近期的科学研究表明,过量摄入含糖饮料(SSB)是导致体重增加的主要因素之一。应对日益严重的肥胖流行的一个选项是通过财政政策抑制含糖饮料消费,例如征收汽水消费税。本文运用Becker-Murphy理性成瘾模型,提供了消费者对含有咖啡因和/或糖的汽水饮料的消费存在理性成瘾的证据。基于这一证据,我们构建了一个动态结构模型,以量化汽水税对汽水购买与消费的影响,并研究成瘾在影响这一效应中的作用。我们通过引入多维成瘾框架对经典理性成瘾模型进行了扩展,从而可以将汽水消费情境中的成瘾分解为两个不同的组成部分:咖啡因和糖。利用参数估计结果,我们基于现实的政策情景开展反事实分析,评估不同税收政策将如何影响汽水购买。例如,一项政策实验表明,仅对含糖汽水类别征收每盎司1美分的税收,将使含糖汽水消费减少50.2%。此外,我们发现,与咖啡因相比,糖在影响替代模式方面似乎发挥着更大的作用。我们进一步考察这些税收如何通过成瘾水平的变化影响福利,并通过比较模型中纳入与不纳入成瘾的估计结果来强调成瘾的重要性。为了理解与汽水税相关的外部性,我们将反事实分析结果与近期医学文献中的因果估计相结合。我们的研究结果表明,在各种税收方案下,个人每年可减少642至717美元的医疗费用。这些结果凸显了汽水税在显著改善公共健康和降低肥胖相关医疗成本方面的潜力。本文由市场营销领域编辑Raphael Thomadsen接收。资助:本研究受南洋理工大学启动基金资助[资助号023220-00001]。补充材料:在线附录及数据文件可从https://doi.org/10.1287/mnsc.2021.02422获取。
Abstract
The obesity rate has grown to epidemic proportions in the United States. Recent scientific studies suggest that excess intake of sugar-sweetened beverages (SSBs) is one of the primary contributors to weight gain. One option to address the growing obesity epidemic is to discourage SSB consumption through fiscal policies such as imposing a soda excise tax. In this paper, we apply the Becker-Murphy model of rational addiction to present evidence that consumers are rationally addicted to the consumption of soda drinks that contain caffeine and/or sugar. Motivated by the evidence, we build a dynamic structural model to quantify the impact of soda taxes on soda purchases and consumption and study the role of addiction in influencing this impact. We extend the canonical rational addiction model by introducing a multidimensional framework of addiction, which allows for the decomposition of addiction in the context of soda consumption into two distinct components: caffeine and sugar. Using the parameter estimates, we conduct counterfactual analyses based on realistic policy scenarios and evaluate how different tax policies would affect soda purchases. For example, one policy experiment indicates that a tax of one cent per ounce only on sugary soda categories would lead to a 50.2% decrease in sugary soda consumption. In addition, we find that sugar seems to play a bigger role in influencing substitution patterns than caffeine. We further investigate how these taxes affect welfare through a change in addiction level and emphasize the importance of addiction by comparing estimation results with and without addiction in the model. To understand the externalities associated with soda taxation, we integrate our counterfactual results with causal estimates from recent medical literature. Our findings suggest that individuals could decrease their medical costs by $642 to $717 per year under various tax schemes. These results underscore the potential of soda taxes to significantly improve public health and reduce obesity-related healthcare costs. This paper was accepted by Raphael Thomadsen, marketing. Funding: This work was supported by a Nanyang Technological University start-up grant [Grant 023220-00001]. Supplemental Material: The online appendix and data files are available at https://doi.org/10.1287/mnsc.2021.02422 .