"Money doesn't buy you happiness but it does bring you a more pleasant form of misery." So quipped Spike Milligan, implicitly agreeing with what has become received wisdom in the science of happiness: being richer does not make you happier, once you have enough income to meet certain basic needs.
It is called the Easterlin paradox, after the scientist who first identified the phenomenon from studies of the Japanese economic boom after the second war. Between 1950 and 1970 wealth grew dramatically, but life satisfaction fell. He explained the inverse relationship by proposing that once basic needs are met it is not absolute income that feeds felicity but relative income: how much you make compared with others.
Economists working on happiness have become very confident of the efficacy of this paradox. Some have even suggested that a government truly concerned with the happiness of its citizens would increase taxes. That would level out relative incomes and so boost satisfaction. Richard Layard, sometimes referred to as the UK's "happiness tsar", has suggested that tax levels at around 60% would not be inappropriate. Such a policy would probably reduce GDP, but then GDP is a faulty measure of wellbeing.
Now, though, new research is threatening to overturn the old orthodoxy. Two economists, Betsey Stevenson and Justin Wolfers, have presented evidence that more money can bring more happiness, if with no absolute guarantees. In short, they have concluded that there is no Easterlin paradox. Talking at the Brookings panel on economic activity, they argued that richer equals happier; richer countries are happier than poorer ones; and as countries become richer they tend to become happier. There is "no evidence of a satiation point beyond which wealthier countries have no further increases in subjective wellbeing." Or to put it another way, GDP actually is a pretty good measure of happiness.
Easterlin, and others since, have got it wrong, they believe, because it is so difficult to compare happiness across different cultures and times - though less so now, as methodologies and questionnaires have become standardised.
Easterlin himself has hit back, arguing that if it was hard to assess subjective happiness in the 1950s, it is still pretty hard to do so now. Also, even with the new evidence, GDP is not consistently linked to wellbeing, notably in China and the US - two rather large anomalies. Stevenson and Wolfers have produced a "very rough draft", Easterlin concludes. Ouch.
As yet, there are no clear indicators as to who will be left smiling at the end of this tussle. In the meantime, it is wise to remain wary of economists brandishing statistics. As Alex Singleton suggested, the science might be at its most flaky, and simplistic, in the very areas where its impact on government policy, and people's lives, would be greatest.