As McKinsey & Co. pointed out last month in its study on the global demand for high-skilled labor, the percentage of labor-intensive, or low-skilled assembly and factory line jobs declined by half since the 1970s;  low-skilled jobs as a percentage of all manufacturing positions declined by 29 percent, while the percentage of manufacturing jobs in capital- and knowledge-intensive areas – those requiring strong math, science, and computer language skills – have and will continue to increase.
RiShawn Biddle via http://dropoutnation.net/2012/07/30/why-algebra-matters-and-why-those-who-think-it-doesnt-are-wrong
It’s just easy and affordable for most companies to send low skilled jobs overseas. People need to really become more intelligent in the United States, we need to have a deeper focus on education as a country, then you will see both sectors rise.