That's a good question.
The measure everyone uses, and the one that I and other people have talked about, is a relative measure, which means it's relative to the median. So a country like the United States, which has a very high median income, is going to have a very high low-income cut-off, which means it's easier to be poor, if you wish, in the United States. You can be poor in the United States with a higher income than you could in, say, Denmark, because it's relative to the wealth of that nation, and the U.S. is a wealthier nation.
Some people have tried to move to a more absolute measure, and as far as I can tell, they found roughly the following. This isn't so much a low-income rate as it is what people earn at, say, the tenth percentile. That is, if you take a look at the people who are in the bottom tenth of the income distribution, what are their earnings--the people who are right at the tenth percentile, if you follow that.
Generally, what people have found is that when you do it that way, the Americans tend to line up pretty well with the Europeans. So although they have a higher relative low-income rate, when you look at absolute purchasing power, at the bottom end among the poorer families it's about the same in the United States as it is in the Nordic countries, for instance.
Is that okay? Are you with me on that?