How the bloody hell does one measure something that varies from individual to individual? What makes one person happy can make another unhappy.
According to the BBC the Coalition intend wasting even more public money (new government = same old government) attempting this pointless exercise.
Just in case anyone from the Coalition happens 'to pass by', let me say what would truly make the people happy is if Cameron and Clegg just 'Foxtrot Oscar'd', the Conservative Party returned to true Conservative policies, the Liberal Democrats returned to 'sitting on the fence' and the Labour Party returned to 'full blown socialism'. At least then the electorate would have a clear cut choice at any future general election!
As is usual, common sense 'Blooms' from the UK Independence Party:
".....it was an attempt "to invoke voodoo sociology in the service of a bigger and interfering state". "I can guarantee that the only results of this proposal will be greater spending, greater bossing around and a decrease in happiness across the board...."