There are large differences in case fatality rates from the coronavirus outbreak across countries, from around 6% in Italy to close to zero in some northern European countries (as of 12 March). This column uses World Value Survey data on the share of people aged 30-49 who live with their parents to show that fatality rates are initially higher in countries with more intergenerational interactions. It provides a warning for how important it is for countries where the elderly and the young live close together in particular to try to contain the virus early on.