4. Consequences of Happiness

Happiness has various effects: Persons considering themselves to be happy act differently in many life circumstances. Happier persons are more productive, in better health, and therefore live longer. The positive consequences of happiness are illustrated using the case of health. The effects can be captured by various methods: A large number of persons are observed over many years; emotions can be manipulated in laboratory experiments; and the impact on health of personal misfortunes such as the loss of a marital partner can be explored. Often it is difficult to establish in which direction the relationship between cause and effect works. To identify the direction, lottery winners are analysed. This analysis shows that higher income and wealth indeed raise happiness, though only for a short period.