It seems that US GDP always seems higher than European GDP. A fact that US pundits always seem to crow about. It seems that there may be a reason for this (other than the fact that the US is a dynamic environment to work in). As Philip Greenspun reports on his blog, if health and education are privatized (as they are in the US), then there are some additional monetary of this reflected in the GDP numbers that are excluded in countries with socialized health and education programmes. A conclusion that Philip attributes to Piketty.
Another thing that inflates GDP is that Americans spend a lot more on litigation than Europeans.
I would be interested if someone did an analysis on how much of an effect this has on GDP.