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...

Countries often spend billions on university research. There is growing interest in how to assess whether that money is well spent. Is there an objective way to assess the quality of a nation's world-leading science? I attempt to suggest a method, and illustrate it with modern data on economics....