Márta Radó

Research problem and specific questions: The increasing use of social media and alternative nicotine products, i.e., e-cigarettes and Swedish snus, poses new threats to stall the progress of tobacco control. Vast research shows how smoking spreads in social networks, but it remains unclear how alternative nicotine products and online interactions affect this spread. Understanding the social network mechanisms underlying nicotine product use is crucial for the design of effective policies. Novel policies for adolescents are needed to prevent nicotine product use at the age when this is typically initiated, even by those who would otherwise never use cigarettes. This project will be the first to identify the network mechanisms of how various nicotine products spread among adolescents and then design a policy intervention to tackle these. We will answer (1) how different nicotine products spread and if alternative nicotine products renormalize cigarettes, (2) how cigarette use spreads online and offline, and (3) what the possible consequences of network-based interventions are, accounting for various nicotine products and online interactions. Data and method: We will collect unique complete social network data of 600 adolescents in Swedish school classes over two waves with information on online and offline social networks and nicotine product use and link this to Swedish registers. We will employ social network analysis methods: (1) exponential random graph models and stochastic-actor-oriented models to investigate the popularity and spread of nicotine products in online and offline social networks and (2) empirically calibrated agent-based models to investigate possible interventions. Societal relevance and utilization: The tobacco industry increasingly employs online campaigns and alternative nicotine products to recruit a new generation of users, but public health interventions lag behind in their response. We aim to provide information on how to prioritize policy implementation to further reduce nicotine product prevalence and inequalities in nicotine product use and help to achieve Sustainable Development Goals 3 and 10. Plan for project realization: This three-year-long project will be approved by the Swedish Ethical Review Authority. The main costs are for researchers’ salaries. The research group consists of sociologists and public health experts with solid experience in collecting and analyzing longitudinal network data and child health behaviors.

In recent years, higher socioeconomic groups started to have more children than lower socioeconomic groups in Sweden and in many other developed countries. Previous research focusing on individuals as independent units had limited power in explaining this polarization in fertility. We will thus use a social network perspective to understand the role of segregated social networks in the fertility behavior of different socioeconomic groups. Using longitudinal population-level social networks consisting of multiple types of relationships (i.e. neighbors, family, and workmates), we will answer (1) how fertility behavior spreads in the social networks for different socioeconomic groups, (2) how use of assisted reproductive techniques spreads in the social networks for the different socioeconomic group, and (3) how family support in someone’s social network influences fertility among different socioeconomic groups. Data will be obtained from several Swedish registers. Quasi-experimental methods (i.e., instrumental variable and small unit analysis) will be applied to distinguish whether people influence each other’s fertility behavior or simply select their relationship based on pre-existing similarities (e.g., fertility intentions). The project will be the first to investigate the role of social networks in forming socioeconomic fertility differentials based on population-level network data, contributing to the understanding of evolving socioeconomic inequalities.