Leader: Comical Cameron's having a laugh at our expense
The problem with happiness is it is not always a quality governments would wish to encourage. What of the deep pleasure enjoyed when the rich and powerful are humbled - that tingling uplift from schadenfreude? Rupert Murdoch's encounter with a shaving foam pie may have shocked MPs but did millions of YouTube viewers keep hitting the replay button?
And not all prime ministers can communicate a concern for happiness with conviction. Chancellor George Osborne might regard unhappiness as a proxy measure of success in his deficit-cutting ambitions. Or there's Gordon Brown, whose demeanour did not exactly radiate happiness to voters Happiness - spontaneous, subjective, capricious, elusive - cannot be manufactured by government. If Mr Cameron wants to conjure up happiness to lift the national mood he can always appoint an official government jester. There's certainly no lack of talent from which to choose.