The World Happiness Report numbers are based only on the Cantril ladder. I don't get why they don't use an average of the Cantril ladder, positive affect, and negative affect. The Cantril ladder asks respondents the following question: "Please imagine a ladder, with steps numbered from 0 at the bottom to 10 at the top. The top of the ladder represents the best possible life for you and the bottom of the ladder repres…
Considering some hypotheticals: Is it possible to both be living your best 10/10 life and be unhappy at times? Is it possible to be living your worst 0/10 life and be happy at times?
If happiness is an emotion, then it is by its nature fleeting and you couldn't maintain a 10/10 or 0/10 happiness as your biochemistry/environment changes constantly, indeed much faster than you'd change the ladder-steps of Cantril. If happiness is more of a personality trait, a semi-permanent descriptor, then it seems more closely associated with the Cantril ladder and life satisfaction.
Personally, I believe happiness results from genetic, short, and long term causes. Every person has a genetic baseline happiness proclivity, then a medium-term multiplier based on their life circumstances (job, relationships, meaning, etc), then a short-term mood-multiplier (I'm happier exercising, playing music, etc. than sitting in traffic or filing paperwork).