They say there's one thing money can't buy: happiness (or love or sex, take it as you want).

A new research proves it literally: sex is better than money in making you happy. That is not to be understood as "being financially poor works", but rather as "being sexually active indeed brings a happy life".

Investigating "happiness economics", the researchers also found that despite the common theory, more financial power doesn't bring you more sex.

The team made up by Dartmouth College economist David Blachflower and Andrew Oswald of the University of Warwick in England searched on the self-reported levels of sexual activity and happiness on a sample of 16,000 people.

They discovered that sex "enters so strongly (and) positively in happiness equations" that they estimate that a higher frequency of sexual contacts from once monthly to once weekly is similar to the happiness level increase brought by an additional $50,000 in income for the average American. "The evidence we see is that money brings some amounts of happiness, but not as much as what economists might have thought. We had to look to psychologists and realize that other things really matter", says Blanchflower.

The researchers found no link between the amount of money and that of sex; people with very different income levels practiced sex with the same frequency. Sex was found to have a deeper impact on the levels of happiness in highly educated, and subsequently richer, people than on lower educational classes.

On average, the happiest individuals were those getting the most and regular sex: married people, or those involved in a relationship, who declared 30% more sexual activity than bachelors. A stable marriage was figured out to bring the same happiness levels provoked by an extra $100,000 earning annually, while divorce was equivalent to a happiness decrease of $66,000 each year.

The rising happiness level could not be strictly connected to marital bliss or more sex. But the "econometric" results correlate with psychological observations: happy people are usually more sexually active. "Many studies confirm that people who are depressed have less sex," said psychologist and sex therapist Dr. Robert Hatfield, of the University of Cincinnati and a spokesman for the Society for the Scientific Study of Sexuality. "Conversely, if you're not depressed -- 'happy,' as some might say -- you're more likely to have more frequent sex."
It is not clear which triggers which, but surely mind and sex fuel each other.