What is the measure of richer? By median income, Japan and South Korea are slightly richer than Spain but poorer than France. They are higher by GDP per Capita,

What is the measure of richer? By median income, Japan and South Korea are slightly richer than Spain but poorer than France. They are higher by GDP per Capita, but I don't think that is a very good measure as it completely ignores extreme income inequality and would list several oil rich nations very high even though only a few very wealthy at the top benefit.