Bad Lighting: Effects of Youth Indoor Tanning Prohibitions

Skin cancer is the most diagnosed cancer in the United States and – unlike other cancers – has been on the rise in recent years, particularly among young women (ACS 2021). Use of indoor tanning beds, which emit cancer-causing UVA light at concentrations higher than natural sunlight, has been shown to dramatically increase the risk of developing skin cancer. In 2009, the World Health Organization officially classified UV-emitting tanning devices as carcinogenic to humans, and major medical organizations such as the American Academy of Dermatology have recommended bans on indoor tanning by minors (WHO 2017).

Despite scientific agreement regarding the health risks of indoor tanning, use of artificial tanning facilities is common in the US, particularly among white girls and young adult women. In 2009, over one in three white high school females reported indoor tanning in the past year according to estimates from the Centers for Disease Control (CDC) (see Figure 1). In recognition of the popularity of indoor tanning among youths, states have adopted a variety of youth-targeted restrictions on indoor tanning to address this public health concern. As of 2020, 32 states had adopted laws completely prohibiting indoor tanning bed (ITB) use by at least some minors, and 22 states applied these ITB prohibitions to all individuals under the age of 18.1

Very little economics research has studied skin cancer or indoor tanning, and to our knowledge no prior work examines youth prohibitions on indoor tanning. This contrasts with extensive work in the economics literature studying other modifiable risk behaviors with youth-targeted prohibitions and minimum legal ages, such as alcohol consumption (Dee 1999; Carpenter and Dobkin 2009), cigarette smoking (Gruber and Zinman 2001; Bryan et al. 2020), e-cigarette use (Friedman 2015), driving (Huh and Reif 2021), dropping out of high school (Anderson 2014), and gun access (Anderson and Sabia 2018). While a public health and medical literature has documented prevalence and trends in indoor tanning behavior and its association with cancer risk (see Watson et al. 2013 for a review), only a handful of studies examine relationships with state policies. Critically, all existing public health studies examining state regulations and ITB use by youths rely on cross-sectional variation in state policies or are single-state evaluations, usually without an untreated control group (Mayer et al. 2011; Guy et al. 2014; Qin et al. 2018).

In this paper we provide the first evidence on the effects of youth ITB prohibitions on a range of tanning-related outcomes. We make several contributions. First, we take an explicitly quasi-experimental approach that leverages within-state changes in youth indoor tanning prohibitions over time to address concerns about unobserved state characteristics and preferences that may contribute both to the presence of tanning bed restrictions and to tanning-related outcomes. This setup allows us to account for time-invariant location-specific attitudes toward tanning bed usage, as well as broader national trends in indoor tanning. Moreover, we make explicit use of within-state variation in the ages of youths who were and were not prohibited by the indoor tanning regulations, allowing us to test sharp predictions about tanning-related behaviors for teens newly bound by a youth indoor tanning prohibition. Second, we consider many more outcomes than have been studied in prior work. By examining changes in tanning-related information-seeking behavior using Google Trends data, our study offers novel insights into the mechanisms through which these prohibitions affect youth indoor tanning. We also offer the first evidence on how these policies affected the tanning salon industry using the National Establishment Time-Series data, allowing us to characterize the broader market wide effects of these policies. This evidence is relevant for both tanning-related health policy and more generally as a way to think about how policies affect economic welfare. Our results are particularly relevant and timely given that the FDA has proposed a nationwide ban on indoor tanning bed use by minors in the United States (FDA 2015). The experiences of US states are likely to produce the most externally valid estimates of the effects of a federal youth indoor tanning ban.

We report several results from this research. First, we find that youth indoor tanning prohibitions significantly reduced indoor tanning behaviors. For example, we find that Google searches for ‘tan’ and ‘tanning’ were significantly less popular following age-based prohibitions on indoor tanning compared to the associated changes in states that did not impose such restrictions. Although Google search data do not indicate whose search behavior was affected, we use other data to provide evidence that youth ITB prohibitions significantly reduced self-reported indoor tanning participation and intensity by high school age girls. These results are observed in youth self-reports from the state Youth Risk Behavior Surveys from 2009-2019. Effects are concentrated among high school age white girls; we find no evidence that youth indoor tanning prohibitions changed tanning behaviors of identically aged boys or black girls. Among white high school age girls, we estimate that a state ITB prohibition reduced the likelihood of indoor tanning by 5.6 percentage points, or about 15 percent relative to the 2009 average for this group. Measured differently, we estimate that youth ITB prohibitions can explain over 20 percent of the overall decline in indoor tanning rates for white high school girls over this period.

We also find clear evidence that youth indoor tanning prohibitions significantly reduced the size of the indoor tanning market. Using panel data on a near universe of tanning salons from the National Establishment Time-Series from 1990 to 2017, we show that state youth indoor tanning prohibitions were associated with statistically significant increases in the likelihood that an indoor tanning salon closed as well as reductions in sales for surviving establishments. Moreover, we find that the negative market size effects of youth indoor tanning prohibitions were stronger for establishments that were likely to have experienced stronger negative demand shocks due to their proximity to middle and high school girls.

Finally, we examine a range of outcomes intended to address possible unintended consequences of state youth ITB prohibitions. We find no evidence that ITB prohibitions were related to youth drinking, smoking, sexual behaviors, weight perceptions, or suicidality for white high school girls, the group whose ITB use was the most directly affected by the policies. In fact, we find evidence that state ITB prohibitions were associated with significant increases in Google search popularity for sun-protective terms such as ‘sunscreen’, and we also find evidence that state ITB prohibitions increased regular sunscreen use by white high school girls.

Taken together, our results suggest that youth prohibitions on indoor tanning were largely successful at reducing indoor tanning by adolescent white girls with relatively little adverse effect except for a predictable and sizable reduction in the size of the indoor tanning salon market. Our results offer a novel demonstration that public health interventions can have important effects on the structure of private markets.

The paper proceeds as follows: Section 2 discusses the institutional background of state indoor tanning prohibitions and other regulations. Section 3 reviews the small economics literature and larger public health literature on skin cancer and indoor tanning, including its relationship with state policies. Section 4 describes the data and outlines our empirical approach. Section 5 presents the results, and Section 6 discusses and concludes.

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