This looks very much like a retread of something thats already been done :

Today’s study comes after the British Medical
Journal decided to find out why life satisfaction in Denmark
substantially and consistently exceeds that in Sweden and Finland, the
two countries most similar to it.

Their hypotheses
ranged from the unlikely (hair colour, genes, food and language) to the
more plausible, such as family life, health and a prosperous economy.

However,
their analysis pointed to two explanatory factors. Firstly, winning the
1992 European Football Championship put Danes in such a state of
euphoria that the country has not been the same since.

Secondly, while Danes are very satisfied, their expectations for the coming year are rather low.

So the key to happiness may lie in the fact that if you lower your expectations enough, you might feel better next year.

Still I have a feeling that this Danes are happy shtick will mean people running around telling us we should be more like Danes; higher taxes, more redistribution and so on. Why not, Oliver James has already made it the basis of a book?

The thing is, it seems not to be the amount of government so much as trust in it:

The report confirmed the old adage that money can’t
buy you happiness. In countries where the population generally said
they trusted the Government and other institutions, a high income made
people happier still.

But in those countries where such trust was lacking – like Italy – even the rich tended to be unhappy.

Another way of putting it is that it’s the quality, not the quantity, of government that aids happiness. Given the lamentable performance of those who rule us, having and paying for more government of the type we already get is unlikely to make us happier.