The Effect of E-cigarette Taxes on Pre-pregnancy and Prenatal Smoking

The rapid growth of electronic cigarettes (e-cigarettes) and other vaping devices is transforming the tobacco marketplace and presenting new challenges for tobacco regulatory efforts. E-cigarettes began to be sold in the U.S in 2007. National surveys indicated that 2014 was the first year that teenagers in the U.S reported being more likely to use e-cigarettes than conventional cigarettes. Lifetime use of e-cigarettes among adults has risen steadily and reached 15% in 2016 (National Health Interview Survey, 2016). E-cigarette use has also been high among pregnant women who smoke cigarettes, a group that is highly motivated to quit smoking during pregnancy and may turn to e-cigarettes as smoking cessation products. One nationally-representative survey suggests that 13.8% of pregnant women currently smoke, 4.9% currently use e-cigarettes, and 28.5% of current smokers also use e-cigarettes (Kurti et al., 2017). One small randomized controlled trial focusing on pregnant women who were unable to quit smoking on their own during pregnancy found that 14% of them used e-cigarettes during pregnancy. Most of them reported e-cigarette use in an effort to quit smoking (Oncken et al., 2017).

Regulatory efforts have followed the surge in e-cigarette use. In August 2016, the US Food and Drug Administration implemented a set of basic regulations of e-cigarettes on a national level, including establishing a national minimum legal purchase age of 18 and affixing warning labels to all electronic vaping products. Parallel to this national effort, state and sub-state governments have passed their own regulations, such as minimum legal purchase age laws that predated the FDA’s law, indoor vaping restrictions, and taxes. By 2016, 10 states and numerous counties/municipalities have banned e-cigarette use in certain indoor locations. Minnesota enacted the first e-cigarette tax in 2010 and, by the third quarter of 2018, a total of eight states have levied taxes on e-cigarettes.

To date, little research has proved the effect of e-cigarette policies on prenatal smoking and birth outcomes. One study found that e-cigarette indoor vaping restrictions decreased smoking cessation among pregnant adult smokers (Cooper and Pesko, 2017), and another study found that e-cigarette minimum legal purchase age laws increased prenatal smoking among teenage pregnant smokers (Pesko and Currie, 2018). Despite these policies raising prenatal smoking rates, birth outcomes remained unchanged. This is likely because nicotine is in both e-cigarettes and cigarettes and is the primary development toxicant in tobacco. To date, no studies have evaluated the effect of e-cigarette taxes.

We use the universe of birth records in the US from 2013 to 2017 to examine the effect of e-cigarette taxes on pre-pregnancy smoking, prenatal smoking, and birth outcomes of birth weight, gestational length, and Apgar 5 score. We use a linear probability model to study the effect of e-cigarette taxes and control for county fixed effects, year-by-month of gestation fixed effects, time-varying tobacco control policies, mothers’ demographic characteristics (e.g. education, race/ethnicity, marital status, payment source), and number of the current birth. Our study will provide the first evidence of the impact of e-cigarette taxes.