According to Mirror, mirror on the wall

...it is undeniable that the average person in the euro area is still about 30% poorer (in terms of GDP per person measured at purchasing-power parity) than the average American, and this gap has barely changed over the past 30 years. Thus even if income per person is growing at almost the same pace as in America, Europeans are still stuck with much lower living standards than Americans.

Then it cites Olivier Blanchard, an economist at the Massachussetts Institute of Technology, on why Europeans work less than Americans. He

concludes that most, but not all, of the fall in hours worked over the past 30 years is due to a preference for more leisure as incomes have increased. Europeans simply enjoy leisure more. Americans seem more obsessed with keeping up with the Jones's in terms of their consumption of material goods. As a result, they may work too hard and consume too little leisure. Their GDP figures look good, but perhaps at a cost to their overall economic welfare.

Yeah, despite being an American myself, I find the Americans overly materialistic, even at the same time that they're more religious than the Europeans. I suspect that with increasing wealth, the Chinese will turn out to be pretty materalistic, too. I wonder if they'll be spiritual, too.