To some degree every available happiness metric is a goodhart, but people in places like Bangalore seem justifiably keen on moving to the high GDP countries. I think the thing that makes GDP per capita PPP or the highly correlated “median income” reliable as proxies for national well being, is that (non-Chinese) governments tend to be really unaggressive at “optimizing” them.
To some degree every available happiness metric is a goodhart, but people in places like Bangalore seem justifiably keen on moving to the high GDP countries. I think the thing that makes GDP per capita PPP or the highly correlated “median income” reliable as proxies for national well being, is that (non-Chinese) governments tend to be really unaggressive at “optimizing” them.