In this paper, we propose a variable selection procedure based on the shrinkage estimation technique for a categorical varying-coefficient model. We apply the method to identify the relevant determinants for body mass index (BMI) from a large amount of potential factors proposed in the...

With the COVID-19 pandemic, the internet has become a key player in the daily lives of most people. We investigate the relationship between mental health and internet use frequency and purpose, 6 months after the first lockdown in the UK, in September 2020. Using data from the UK Household...