http://en.wikipedia.org/wiki/Image:Percentage_population_living_on_less_than_1_dollar_day.png

The US poverty rate you refer to is defined as a percentage of the median income, and is therefore in fact not a measurement of poverty at all, but a measurement of income distribution, just as all so called "relative poverty" measurements are.

The US has low poverty levels. Anything else is pure misinformation.

Also note how Chile is doing well, and better than it's neighbours. Also, Chile has a very good life expectancy,
http://en.wikipedia.org/wiki/Image:Life_expectancy_world_map.PNG

And a good HDI value:
http://en.wikipedia.org/wiki/Image:HDImap_spectrum2006.png

All things that largely has happened thanks to a relatively liberal economic policies. (Yes, relatively, that is about as liberal as Sweden. The idea that Chile is some sort of superneoliberal experiment is a pure myth).