This study is a national-level randomized control trial to measure the effects of dressing in professional attire by adolescents on regulation compliance-related behaviors of electronic cigarette (e-cigarette) retailers defined by both age verification and potential underage sales. The corresponding null hypothesis that will be tested is that dressing in professional attire by adolescents will have no effect upon retailer behaviors in regulation compliance. The secondary objectives are to determine the impacts of type of dress by adolescents on marketing and communication strategies adopted by retailers, as well as to document the differences in the behaviors between e-cigarette and tobacco retailers.

Electronic cigarette (e-cigarette) use has been growing dramatically and poses a significant public health threat to adolescents in China. After the online sales of these products has been banned, purchases from brick-and-mortar stores became the only legal option for the users. However, little research has been conducted to document sales behaviors of the physical retailers and identify the associated factors. The study will investigate the extent to which dressing in professional attire by adolescents on regulation compliance in retailer behaviors, including inquiring about age, requesting identity cards for age verification, and completing transactions even when identity cards are not presented. Adopting the simulated client method, the study will collect information on regulation compliance, store environment, product availability, and marketing strategies through interacting with retailers across China. Considering that e-cigarette retailers are predominately located in the most densely populated cities, the investigators will include approximately 1,080 e-cigarette retailers from 36 cities, including 4 municipalities directly under the Central Government, 27 provincial capital cities, and 5 cities specially designated in the state plan. Store addresses and contact information will be obtained through web scraping from the AutoNavi map (the most popular map app in China). The investigators plan to randomly sample 32 retailers in each city if the number allows, and cities with less than 32 retailers identified will all be included. To capture reality, retailers will not be informed during visit. The sampled ones within each city will be randomized into the intervention and control group, with a balance gender ratio of the simulated clients. These clients will be recruited from university students younger than 20 years old, who can easily be considered as minors (under 18) when purely judged by their appearance. Clients visiting retailers in the control group will dress in school uniforms and carry a school bag, while those in the intervention group will dress in professional attire with a business-style backpack for males or a leather bag for females. The clients will record retailer responses, including (1) inquiring about age verbally, (2) requesting identity cards for age verification, and (3) whether retailers still sell products even when identity cards are not presented. For each e-cigarette retailer, the nearest tobacco retailer identified through the AutoNavi Map will be used for comparison to document the differences in the behaviors between the two types of retailers. Additionally, communication and marketing strategies, e.g., mentioning available flavored products, dissuading clients not to purchase, are also collected.

Inclusion Criteria:

• Retailers can be identified from the AutoNavi Map through keyword searches
• Retailers have reachable contact information
• Retailers are contacted and claim being open for business on a regular basis
• Include only one retailer if multiple ones have the same contact information

Exclusion Criteria:

• Retailers that are not located in main districts of the cities (usually old town and economically developed central areas)
• Perceived danger surrounding the retailers (e.g., remote alleys with no pedestrians at all)
• Closed when arriving
• Retailers that cannot be located based on map information