New York - Does money buy happiness? It's sometimes said that scientists have found no relationship between money and happiness, but that's a myth, says University of Illinois psychologist Ed Diener.

The connection is complex, he says. But in fact, very rich people rate substantially higher in satisfaction with life than very poor people do, even within wealthy nations, he says.

"There is overwhelming evidence that money buys happiness," said economist Andrew Oswald of the University of Warwick in England. The main debate, he said, is how strong the effect is.

Oswald recently reported a study of Britons who won between $2,000 and $250,000 in a lottery. As a group, they showed a boost in happiness averaging a bit more than 1 point on a 36-point scale when surveyed two years after their win, compared to their levels two years before they won.

Daniel Kahneman, a Nobel-Prize winner and Princeton economist, and colleagues recently declared that the notion that making a lot of money will produce good overall mood is "mostly illusory."

They noted that in one study, people with household incomes of $90,000 or more were only slightly more likely to call themselves "very happy" overall than were people from households making $50,000 to $89,999. The rates were 43 percent versus 42 percent, respectively. (Members of the high-income group were almost twice as likely to call themselves "very happy" as people from households with incomes below $20,000.)

But other studies, rather than asking for a summary estimate of happiness, follow people through the day and repeatedly record their feelings. These studies show less effect of income on happiness, Kahneman and colleagues said.

There is still another twist to the money-happiness story. Even though people who make $150,000 are considerably happier than those who make $40,000, it's not clear why, says psychologist Richard E. Lucas of Michigan State University.

Does money make you happier? Or does being happier in the first place allow you to earn more money later, maybe by way of greater creativity or energy? Or does some other factor produce both money and happiness? There's evidence for all three interpretations, Lucas says.

In any case, researchers say any effect of money on happiness is smaller than most daydreamers assume.

"People exaggerate how much happiness is bought by an extra few thousand," Oswald said. "The quality of relationships has a far bigger effect than quite large rises in salary.... It's much better advice, if you're looking for happiness in life, to try to find the right husband or wife rather than trying to double your salary."