Most Americans have a standard of living which the majority of Europeans will never come any where near. The really prosperous American regions have nearly twice the affluence of Europe. It is worth reminding ourselves what this means. In these regions the average American can get exactly twice as much of everything as the average European. Which goes to show the importance of an economic policy to stimulate growth.
The study has a number of interesting factual and statistical comparisons, for those of us who enjoy such things.
UPDATE: Tyler Cowen has an answer to my discussion question, plus more information, in a post that also links to the Bergström-Gidehag paper.