DOCTORS and policymakers in the rich world are increasingly worried about loneliness. Researchers define loneliness as perceived social isolation, a feeling of not having the social contacts one would like. To find out how many people feel this way, The Economist and the Kaiser Family Foundation (KFF), an American non-profit group focused on health, surveyed nationally representative samples of people in three rich countries. The study found that over 9% of adults in Japan, 22% in America and 23% in Britain always or often feel lonely, or lack companionship, or else feel left out or isolated.
One villain in the contemporary debate is technology. Smartphones and social media are blamed for a rise in loneliness in young people. This is plausible. Data from the OECD club of mostly rich countries suggest that in nearly every member country the share of 15-year-olds saying that they feel lonely at school rose between 2003 and 2015.