"A former boss of mine, the late U.S. Secretary of Labor W. Willard Wirtz,1 used to tell people that when there is a mismatch of workers and jobs, employers have two choices: they can adjust the wages offered or they can seek to adjust the work force. Routinely, he said, they chose the latter. That this choice always exists is rarely mentioned by employers, who, instead, argue that there is a "labor shortage", never finishing their thought by adding "at the wages we are willing to pay".
Are there some U.S. skills shortages that cannot be solved by raising wages and changing training patterns? Of course, but they involve thousands of jobs, not hundreds of thousands or millions of them. If a university seeks a professor of Mongolian languages and literature who must have a PhD and a native's skill with that language, the university should be able to recruit overseas; so should a zoo that needs a veterinarian really skilled with the diseases of the water buffalo.
But nonimmigrant worker programs started decades ago to handle such one-off shortages have morphed over time into massive admissions systems that not only fill jobs with aliens that could have been filed by residents (citizens and green card holders) they lower wages for all concerned where they concentrate. Thus, these systems impose both displacement and wage-depression impacts on the U.S. labor markets.
Are There Really Jobs Americans Won’t Do?
Of the 472 civilian occupations, only six are majority immigrant (legal and illegal). These six occupations account for 1 percent of the total U.S. workforce. Moreover, native-born Americans still comprise 46 percent of workers even in these occupations.
Many jobs often thought to be overwhelmingly immigrant (legal and illegal) are in fact majority native-born:
Maids and housekeepers: 51 percent native-born
Taxi drivers and chauffeurs: 58 percent native-born
Butchers and meat processors: 63 percent native-born
Grounds maintenance workers: 64 percent native-born
Construction laborers: 66 percent native-born
Porters, bellhops, and concierges: 72 percent native-born
Janitors: 73 percent native-born
Although illegal immigrants comprise a large share of workers in agriculture, farm workers are only a tiny share of the total labor force. Consistent with other research, just 5 percent of all illegal immigrants work in agriculture.