For the same baseline level of internal well-being, people will respond to the question "how happy are you?" differently depending on their culture. Do you understand how this presents a problem when measuring happiness across cultures? That is why I refer to it as subjective. Cultures change over time, so a change in the HPI might simply be a reflection of that.
That being said, I do not believe that just because a measure is subjective, it is useless. Of course it's useful. It's just important to understand what exactly you're measuring.
For the same baseline level of internal well-being, people will respond to the question "how happy are you?" differently depending on their culture. Do you understand how this presents a problem when measuring happiness across cultures? That is why I refer to it as subjective. Cultures change over time, so a change in the HPI might simply be a reflection of that.
That being said, I do not believe that just because a measure is subjective, it is useless. Of course it's useful. It's just important to understand what exactly you're measuring.