Closer to home, in Guangdong the Communist Party has pledged to make improving 'gross domestic happiness' the main objective of its next five-year plan and has adopted the slogan 'Happy Guangdong' in an attempt to spread the message.

And here in Hong Kong, the Heritage Foundation, which this month declared our city to be the freest economy in the world, said that the more economic freedom a country enjoys, the happier its people will be. Apparently, solid property rights, low levels of government involvement in the economy and consumer choice are the key to happiness.

The first of these examples is especially worrying. Despite what America's third most senior politician might think, nowhere in the US Constitution or its 27 amendments is the word 'happiness' ever mentioned.

All that stuff about 'life, liberty and the pursuit of happiness' is actually from the Declaration of Independence, not the constitution.

But the other examples are troubling too. Usually, when politicians start talking about how the economy isn't everything and that happiness is important too, it is a sure sign that they have made a mess of economic policy and that growth has stalled, inequality has shot through the roof, unemployment is on the rise or inflation is out of control.

Happiness, it seems, is a much abused quality. The trouble is that happiness is notoriously hard to define and measure, which means it can be suborned in the name of all sorts of dubious causes.

Some people claim material well-being is the key to happiness. Others reject this, maintaining that health, education and an unpolluted environment are the essential elements. Right-wingers like the Heritage Foundation, believe the road to happiness is found through greater economic freedom.

The left, meanwhile, argues that conspicuous consumption by a wealthy few breeds envy and frustration among the mass of poor.

They say equality of income is essential for a happy society. In an attempt to examine some of these claims, Monitor has been looking at the available data. Happiness is a tricky one, but clearly the best way to determine whether someone is happy or not is to ask them.

This is exactly what the Gallup Organisation does, asking people in countries around the world 'on a scale of one to 10, all things considered, how satisfied are you with your life as a whole?'

In Gallup's 2009 survey, the title of happiest nation in the world went to the Central American country of Costa Rica, with a score of 8.5. At the other end of the scale, the unfortunate East African country of Tanzania could muster a score of only 2.4, considerably lower, for example, than the occupied territories of Palestine.

In general, however, as the first chart below shows, there is a clear correlation between material well-being, as measured by gross domestic product per capita for 2009, and Gallup's subjective satisfaction score.

Broadly, the richer an economy is, the happier its people.

A sample of 126 countries, gives a Spearman's rank correlation co-efficient between happiness and GDP per capita of 0.8 (where one would be a perfect correlation and zero no correlation). That's pretty tight. Happiness and material well-being walk hand-in-hand.

Next, equality of income may be a nice idea, but it turns out not to be very important for happiness. As the second chart below shows, there is little clear correlation between a low Gini co-efficient of inequality and subjective satisfaction. The same 126 nation sample gives a Spearman co-efficient of just 0.24, not far off zero.

But if the left's claims are dubious, then so are the right's. As the third chart shows, there is a correlation between happiness and economic freedom, but a poor one.

Our sample gives a Spearman co-efficient of just 0.57, which is really nothing much to right home about. Certainly in this case, the correlation is far too weak to indicate cause.

So there you are, despite all sorts of statistical claims, it turns out that by far the closest correlation is between happiness and material wealth. On the whole, people in rich countries are happier.

So if the government starts blathering about how the economy isn't so important and that happiness is the main thing, you will know it is an ominous sign.