Which is the better economic system? Western Europe's? Or the one in the United States? There is a Web debate, here and here, among other places, prompted by Jim Manzi's assertion that Europe's share of the world economy has collapsed since 1980, caused, he implies by its social-welfare state.

Says NYT's Paul Krugman in today's column:

But the story you hear all the time — of a stagnant economy in which high taxes and generous social benefits have undermined incentives, stalling growth and innovation — bears little resemblance to the surprisingly positive facts. The real lesson from Europe is actually the opposite of what conservatives claim: Europe is an economic success, and that success shows that social democracy works.

Tyler Cowen suggests several thoughtful ways of looking at this, including posing this highly important question, which gets at the heart of America's genius:

4. One question is whether the U.S. or Europe does a better job of elevating poor immigrants to higher income levels. You would think egalitarians would be obsessed with this issue, but they're not. In fact most of them hardly mention it.

I can't immediately find any stats or studies, but I assume the U.S. wins in this category by a mile.