- Adult general population 67 nations followed 10 to 40 years 1946 to 2011
- Survey name:
- Survey series: findings of which are listed in World Database of Happiness
- N = 3000000
- Non Response:
Multiple asesment methods
Mostly face-to-face interviews
- Authors's label
- Change average happiness
- Our Classification
- Difference in responses to equivalent questions on happiness in the same country over the years.
Time series with at least 2 observations of at least 10 years difference.