The cynic in me says such graphs are (figuratively) propaganda by the 1% (of 1% in wealth, not income), in that now we can define what the masses are "ok" with while we, the 1% of the 1%, can accelerate our gains further. Let the rest of them have crumbs and be content.
I'm probably being too cynical though. It's just surprising given the reputation of countries like Denmark and Norway for being happy, that any study could possibly leave them out.
Or, according to the World Happiness report 2013: 1. Denmark, 2. Norway, 3. Switzerland, 4. The Netherlands, 5. Sweden. The US ranks 17th.
Source: http://unsdsn.org/files/2013/09/WorldHappinessReport2013_onl...
The graph they have included the 25 most populous countries, and is already a mess (lots of overlapping things). The Scandanavian countries didn't even make the cut on that one, the Economist probably took the ones that were the furthest apart. Maybe if all the Scandinavian countries fused together they could have made it?
For example: is Norway happy because they have a small population with massive, well-managed oil reserves to pay for their social services? Or are they happy because with a smaller population it's easier to gain a consensus vote for alternative ways of life (eg. social democracy)? Whereas say, the USA might always be stuck with a capitalist democracy because the large population is too big to influence easily.
The oil reserves don't pay for the social services. Some of the reserves are spent in the budget, but that is mostly skimming off the "interests", and there are restrictions put in place on how much you can use (maybe you already knew this; your wording was a bit ambiguous).
http://www.economist.com/news/leaders/21571136-politicians-b...
If there is an agenda somewhere, it's probably not on the part of The Economist (I don't know enough about The Economist to comment on more than their apparent public face overall).
It's almost impossible to find an article about countries overall happiness without discussing the Scandinavians at the top, so their absence was conspicuous. Add in the fact that the article is pro-capitalism / money making, and the US are at the top of their happiness scale... It's contrary to the usual message, so I thought it worth pointing out.
The common money-happiness theory seems pretty ridiculous. As though people are happy earning $65k a year and paying on their mortgage for 30 years, worrying about education for their kids, worrying about saving a few grand, worrying about paying the car payment, etc - versus making $500k a year and not having a mortgage at all, sending your kids to Stanford, and never worrying about The Bills.