A jubilee often triggers backward-oriented reflections, sometimes nostalgic. A jubilee can also be used as an excuse for looking forward. This special issue is composed in honour of åke E. Andersson, delayed in the sense that the anniversary (60 years) dates back to 1996. The contributions to this volume have also gone through a maturing process in the form of reviews and revisions. The contributions are organised in three thematic groups. The themes appear in the sequence "Evolution", "Welfare", and "Interaction".