This paper studies a famous unsolved puzzle in quantitative social science. Why do some nations report such high levels of mental well-being? Denmark, for instance, regularly tops the league table of rich countries' happiness; Britain and the US enter further down; some nations do unexpectedly...

This paper examines a famous puzzle in social science. Why do some nations report such high happiness? Denmark, for instance, regularly tops the league table of rich nations' well-being; Great Britain and the US enter further down; France and Italy do relatively poorly. Yet the explanation for...