There's a lot that we've not seen so far in this election campaign. One of the many absences has been any discussion of happiness policy. This is odd, given that back in 2006 Mr Cameron said:

Improving our society's sense of well-being is, I believe, the central political challenge of our times.

You might that the financial crisis overturned this belief. Perhaps it shouldn't have, because well-being might be one solution to slow growth. Some new research claims:

Average local happiness is positively correlated with both R&D intensity and firm investment after controlling for firm and local area characteristics.

To me, this seems intuitive; happier people are more likely to be optimistic, and optimism - animal spirits - raises investment.

This, though, is only one of several channels through which higher well-being might boost economic growth:

- Research by Alex Bryson and colleagues has found that "workplaces with rising employee job satisfaction also experience improvements in workplace performance." This corroborates a finding by Daniel Sgroi.

- People who have good social networks - which are a major contributor to happiness - are more likely to find work quickly and have better job matches.

- There's a strong correlation between happiness and trust. And higher trust means higher economic growth - because trust can overcome market for lemons problems and also encourage lending and investment.

These mechanisms suggest that policies that increase subjective well-being - such as ones to improve job satisfaction, social capital and inter-personal trust - might also increase economic growth. As Charles Kenny has written (pdf):

Actions that improve happiness and the strength of social interaction are good in their own right and might have the added advantage of encouraging growth.

This is an example of John Kay's obliquity: we can sometimes achieve one objective by striving for another.

This, of course, would be a futile observation if policy were unable to increase well-being. But perhaps it can. A report by the Legatum Institute has suggested several possibilities: better mental healthcare; encouraging parents and schools to nurture soft skills;encouraging voluntary work; ensuring that the built environment encourages sociability;creating full employment; and empowering people in work and in politics.

Of course, you can be sceptical about each individual observation here. For example, Ben Southwood has suggested that the correlation between happiness and investment might be due to an omitted variable; IQ, for example, would raise both.

However, I suspect that risk-reward considerations favour happiness policy. In the best case, it might boost growth - and given the threat of secular stagnation we need all the help we can get. But in the worst case, little harm is done. In this sense, happiness policy could be close to a free hit.

Which poses the question: why isn't it on the agenda?

I suspect that it's for disreputable reasons. Happiness policy looks like gawd-help-us soppiness. It's therefore inconsistent with the image of macho managerialism of "tough choices" and "strong leaders" which our politicians want to project - and which our vile philistine media demands.