On the face of it, this assertion seems implausible. Immigrants and low-skilled foreign workers in general are highly concentrated in a few states. The "big six" are California, Florida, Illinois, New Jersey, New York and Texas. Even within those states, immigrants and low-skilled foreign workers are concentrated in a few metropolitan areas — while there are many in New York City and Chicago, relatively few are in upstate New York or downstate Illinois.
Yet even in areas with few immigrants, grass is cut, groceries are bagged and hotel sheets are changed. Indeed, a large majority of low-skilled workers are native to the United States. A look at the 2000 census is instructive: among males age 25 to 64 years employed that year, of those with less than a high school diploma, 64 percent were born in the United States and 36 percent were foreign born.
Other Americans nominally graduated from high school but did not learn a trade or acquire the literacy, numeracy or decision-making skills needed for higher earnings. Still others suffer from a physical or emotional ailment that limits their labor productivity. And some low-skilled jobs are performed by high school or college students, housewives or the retired who wish to work part time. Put simply, there are no low-skilled jobs that American workers would not and do not do.
Over the past two decades the number of low-skilled workers in the United States has increased because of immigration, both legal and illegal. This increase in low-skilled workers has contributed...