While hobbies keep many in the northern Swedish city of Luleå going through the cold dark winter months, loneliness remains a problem, especially among 16 to 29 year-olds. So authorities in Luleå have launched a campaign to encourage people to say hello to one another. The Säg hej! (say hello!) campaign aims to create a friendlier city by nudging people towards small but significant social interactions. Adverts are running on buses, and workshops are being held in schools. Åsa Koski, who works for Luleå municipality, came up with the idea for the campaign. She wants the city, which is undergoing a period of rapid growth as it tries to attract tens of thousands of new people to work in "green" industry and other services, to stay pleasant, safe and friendly even as it grows. "Research shows that it has an effect on health and often an effect on wanting to help each other. If you say hi to your neighbors you are more likely to help them."