Love, life and happiness are the key elements of this dissertation. The long-term development of happiness, or more precisely, subjective well-being, and its determinants are studied in a young adult sample. That is where "life" comes in. When crossing the bridge from childhood to adulthood, people experience many transitions, for instance in their living arrangements and occupational activity. In studying the consequences of these
transitions, a life-course perspective is taken, which implies atttention to the combination of
different events and to the long-term effects of events. With respect to these events, the focus is on the relationship domain, because many events happen in this domain in young
adulthood. Based on analyses with the longitudinal Panel Study on Social Integration in the
Netherlands and the European Social Survey, empirical findings show the importance of relationships for a young adult's level of well-being, and the extent to which the effects are lasting. The study shows how both individual and country characteristics have an impact on these effects.