"Money can't buy me love," as the song goes, but most people think it'll buy you a bunch of reasons to be happy. At the lower end, according to most studies, that's probably true — relative improvements in economic conditions can mean a substantive difference in the subjective judgment of happiness. But, up here at the top of the worldwide economic scale, it's not really as true.
After a certain point, the marginal utility of extra money on a micro level is going to be almost nil because you'll just be keeping up with the Joneses and buying more crap and remaking yourself to try and externally approximate happiness or what you looked like when you were happy once without actually doing anything about being happy. It holds true on a macro-level, too. But, because this is marginally an article about economics, the economist in me would like to point out that there are government policies (other than increasing GDP) that can make a difference in a country's subjective happiness levels "such as maintaining stable families and friendly communities, reducing joblessness, providing adequate health care, and guaranteeing more personal freedom." But we don't like to do that because we're a nation of bootstrappers and DIYers and we're not a welfare state so, hooray for increasing GDP and getting ourselves happy on our own.
By the way, on a completely unrelated note, Americans spent more than the GDP of Bolivia on plastic surgery last year alone ($13.2 billion). In a more unrelated note, sales of antidepressents in 2006 in the U.S. were $20.6 billion. I'm not sure that our plans to find happiness in money or consumption are working, but whatever. I'm sure Priscilla can tell us. She looks happy enough.
Happiness Is ... [Portfolio]
Americans Putting Up The Dough For Plastic Surgery [Houston Chronicle]