Here, first (via Sullivan), is Florida's idea, which tracks with one general assumption of mine:
It is not just the level of economic development that matters, but its nature and type. The past several decades have seen a shift from older industrial-style economies and societies to newer post-industrial ones characterized by higher levels of knowledge-based, professional, and creative jobs, more highly educated populations, and a shift toward what Ronald Inglehart has dubbed "post-materialist values" -- a diminished commitment to traditional authority and institutions and a shift toward self-expression, openness, and tolerance. My recent research with Charlotta Mellander and Jason Rentfrow finds evidence that post-industrial socioeconomic structures and post-materialist values matter to the happiness of nations, especially of the most advanced nations...