Via Robert H. Frank - MIT Press:

“In effect, I wish to propose two different answers to the question “Does money buy happiness?” Considerable evidence suggests that if we use an increase in our incomes, as many of us do, simply to buy bigger houses and more expensive cars, then we do not end up any happier than before. But if we use an increase in our incomes to buy more of certain inconspicuous goods–such as freedom from a long commute or a stressful job–then the evidence paints a very different picture. The less we spend on conspicuous consumption goods, the better we can afford to alleviate congestion; and the more time we can devote to family and friends, to exercise, sleep, travel, and other restorative activities. On the best available evidence, reallocating our time and money in these and similar ways would result in healthier, longer– and happier–lives. "