Richard Florida on What Makes Nations Thrive:

Our results indicate that the factors that contribute to happiness differ in high- and low-income countries. In low-income nations (defined as those with less than $11,000 in per capita GDP), happiness turns on income. But it matters much less in high-income countries. In these countries, people are affluent enough to cover the basics which are essential to a base level of happiness. Two factors matters in particular over and above income in these more well-off nations. The first is the nature of the job market: people are happier in affluent nations where more of them work in knowledge-based, creative, and professional jobs and fewer work in blue-collar working class jobs. Values matter too, especially openness and tolerance toward ethnic and racial minorities and toward gay and lesbian people.