In this episode of Policy Matters, hosts Matt Dickson and Franz Buscha talk to Neil Davies, Senior Research Fellow at the MRC Integrated Epidemiology Unit, University of Bristol. Neil is a statistical epidemiologist, so Franz and Matt begin by finding out what life has been like for an epidemiologist since the COVID-19 pandemic began. Neil then explains his recent work showing how some of the myriad statistics we’re seeing relating to coronavirus suffer from their survey design, which can generate misleading apparent relationships between COVID-19 risk and individual characteristics, such as smoking. Next, Neil explains the statistical technique known as ‘Mendelian Randomisation’; which uses natural variation in our genes to help understand how health conditions and other individual characteristics impact on health and other social and economic outcomes. Matt, Franz and Neil go on to explore some of Neil’s recent research using this technique, which shows how education and intelligence impact the risk of developing Alzheimer’s disease, how BMI affects later outcomes, and why continuing longer in school might lead to increased costs at the opticians!