“As with last year’s report, we have again assembled the available international happiness data on how people rate both their emotions and their lives as a whole. We divide the available measures into three main types: measures of positive emotions (positive affect) including happiness, usually asked about the day preceding the survey; measures of negative emotions (negative affect) again asked about the preceding day; and evaluations of life as a whole. Together, these three types of reports constitute the primary measures of subjective well-being. The three main life evaluations are the Cantril ladder of life, life satisfaction, and happiness with life as a whole. Happiness thus appears twice, once as an emotional report, and once as part of a life evaluation, giving us considerable evidence about the nature and causes of happiness in both its major senses.”