Russian novelist Tolstoy had much to say on the subject. His theory was "happy people have no history".
Which brings me to Paraguay.
This Latin American republic was the poll's big winner - the happiest country out of 138 surveyed.
Geographically it's one of the most isolated countries in the world. But one that maintains strong links to its indigenous language and culture, which goes back at least a millennium before the Spaniards conquered the territory in the 16th century.
Its colourful history deals Tolstoy's theory a crushing blow.
So, what can we more miserable sods learn from blithesome Paraguay?
Maybe nothing. Its economy is by all accounts an enviable one. But here's the thing - it's landlocked.
A country without a beach? That just won't do.
Obviously, we Kiwis gauge joy by other measures, proximity to the coast being one yardstick.
Anyway, before I'm prepared to clap along with Pharrell Williams, I'm content with the knowledge the elusive pursuit of happiness will remain so.
