The world's happiest countries and why so?

See Christopher Helman's article on this in Forbes. He bases this on Legatum Prosperity Index. And this is not solely based on economic prosperity but things like health, social cohesiveness, individual freedom, opportunity and even politics. Norway leads the way as the happiest country, with Denmark, Sweden and Finland following closely. What do these nations have in common? "Being an electoral democracy is almost a given." "They are all borderline socialist states, with generous welfare benefits and lots of redistribution of wealth. Yet they don't let that socialism cross the line into autocracy."Along those lines opportunity to start and maintain a business is a key factor. But what makes for that success? The "you didn't build that" social aspects that enable business success: "This means low business startup costs, lots of cellphones, plenty of secure Internet servers, a history of high R&D spending." They didn't mention roads and bridges, or court systems to enforce business protections, but these are social factors too.