Love it.

I remember reading something about the marginal utility of happiness being reduced beyond an income of about US$75,000 (which allows you to meet your basic needs).

If you’re on $150k a year – it doesn’t mean you’re twice as happy as someone with $75k.

You can probably do similar overlays based on religions, or life expectancy and other interesting angles. Does being a Hindu mean you’re happier? Does living longer make any difference?