How to use it
For most people, more income does add daily happiness, so ambition isn't shallow. For people unhappy for other reasons, money stopped helping early. Build wellbeing alongside it, not "after the exit".
How sure we are
P Evidence: promising. Good studies, but small or few. Use it and keep checking.
Sources
Killingsworth, Kahneman & Mellers 2023 (adversarial collaboration, one large dataset).
Not medical, legal or financial advice.