Using Search Query Surveillance to Monitor Tax Avoidance and Smoking Cessation following the United States' 2009 “SCHIP” Cigarette Tax Increase

Smokers can use the web to continue or quit their habit. Online vendors sell reduced or tax-free cigarettes lowering smoking costs, while health advocates use the web to promote cessation. We examined how smokers' tax avoidance and smoking cessation Internet search queries were motivated by the United States' (US) 2009 State Children's Health Insurance Program (SCHIP) federal cigarette excise tax increase and two other state specific tax increases. Google keyword searches among residents in a taxed geography (US or US state) were compared to an untaxed geography (Canada) for two years around each tax increase. Search data were normalized to a relative search volume (RSV) scale, where the highest search proportion was labeled 100 with lesser proportions scaled by how they relatively compared to the highest proportion. Changes in RSV were estimated by comparing means during and after the tax increase to means before the tax increase, across taxed and untaxed geographies. The SCHIP tax was associated with an 11.8% (95% confidence interval [95%CI], 5.7 to 17.9; p<.001) immediate increase in cessation searches; however, searches quickly abated and approximated differences from pre-tax levels in Canada during the months after the tax. Tax avoidance searches increased 27.9% (95%CI, 15.9 to 39.9; p<.001) and 5.3% (95%CI, 3.6 to 7.1; p<.001) during and in the months after the tax compared to Canada, respectively, suggesting avoidance is the more pronounced and durable response. Trends were similar for state-specific tax increases but suggest strong interactive processes across taxes. When the SCHIP tax followed Florida's tax, versus not, it promoted more cessation and avoidance searches. Efforts to combat tax avoidance and increase cessation may be enhanced by using interventions targeted and tailored to smokers' searches. Search query surveillance is a valuable real-time, free and public method, that may be generalized to other behavioral, biological, informational or psychological outcomes manifested online.

吸烟者可借助网络维持吸烟习惯或戒除烟瘾。在线售烟商售卖降价或免税卷烟，以降低吸烟者的消费成本；健康倡导者则通过网络推广戒烟服务。本研究围绕美国2009年《州儿童健康保险计划（State Children's Health Insurance Program, SCHIP）》联邦卷烟消费税上调，以及另外两起州级卷烟消费税上调事件，探究了吸烟者的避税搜索与戒烟搜索查询的驱动机制。在每一次消费税上调前后的两年周期内，我们将征税地区（美国全国或美国某州）居民的谷歌关键词搜索数据，与免税地区（加拿大）居民的同类搜索数据进行对比。搜索数据被归一化至相对搜索量（relative search volume, RSV）标尺：以搜索占比最高的项赋值为100，其余项的搜索占比则按其相对最高占比的比例进行缩放。通过对比征税地区与免税地区在税改期间、税改后与税改前的搜索量均值，估算相对搜索量的变化幅度。SCHIP联邦消费税上调与戒烟搜索量的即时增长11.8%相关（95%置信区间[95%CI]：5.7~17.9；p<0.001）；然而此类搜索很快便趋于平缓，在税改后的数月内，其与加拿大地区预税前搜索量的差异基本消失。与加拿大地区相比，避税搜索量在税改期间及税改后数月分别增长27.9%（95%CI：15.9~39.9；p<0.001）与5.3%（95%CI：3.6~7.1；p<0.001），这表明避税搜索是更为显著且持久的行为响应。州级消费税上调的趋势与此类似，但显示出不同税改之间存在较强的交互效应。当SCHIP联邦税改紧随佛罗里达州的州级税改实施时，相较于未紧随的情况，会引发更多的戒烟与避税搜索。针对吸烟者的搜索行为制定精准定制化的干预措施，或可强化打击避税行为与推动戒烟工作的成效。搜索查询监测是一种极具价值的实时、免费且公开的监测手段，可推广应用于其他在线呈现的行为、生理、信息或心理相关结果的监测。