Impacts of Border Enforcement on Unauthorized Mexican Migration to the United States
Published on: Sep 26, 2006

In recent years, immigrants have accounted for more than 90% of the labor force growth in some regions of the U.S., like the Mid-West and the Northeast.  These regions are experiencing a population implosion because of both low fertility and out-migration by native-born workers.  Newly arriving immigrants are heading for these labor-short parts of the country, as well as cities in the Southeast and the Rocky Mountain states that have robust job growth.  These “new gateways” for immigration absorbed far more immigrants during the past decade than traditional gateway cities like Chicago and Los Angeles.  Migrants from Mexico, in particular, are dispersing themselves geographically to a much greater extent than previous generations of Mexican immigrants — a healthy trend, because it means that they are not piling up in already saturated labor markets where they might depress wages for other workers.

As immigrants have always done, today’s immigrants are filling particular niches in the U.S. economy.  In recent years they have accounted for most of the employment growth in occupational categories like cashier, janitor, kitchen workers, landscape maintenance worker, construction worker, and mechanic.  The attributes that these jobs have in common are low-skill, low-wage, manual, and often, dirty, repetitive, and dangerous.

In California, immigrants have come to dominate virtually all low-skill job categories,  with over 90% of the state’s farm workers, two-thirds of construction workers,  and 70% of the cooks in restaurants being foreign-born. At the national level, unauthorized immigrants are heavily concentrated in service occupations, followed by construction and manufacturing.  Only 4% of the unauthorized immigrants in the country today are estimated to be working in agriculture.  But agricultural work is still the occupation most dominated by unauthorized immigrants.  According to recent estimates by the Pew Hispanic Center, about a quarter of all farm workers in the country are illegal immigrants; 17% of all cleaning workers; 14% of all construction workers; and 12% of all food preparation workers.

It is important to recognize that, at this point in time, the U.S. demand for immigrant labor is structural in character.  It is deeply embedded in our economy and society.  The demand no longer fluctuates with the business cycle.  Our research on immigrant-dependent firms in San Diego County since the early 1980s has shown that even during recessions, such employers continue to rely on and hire new foreign-born workers.  The job applicant pools of firms that depend heavily on immigrant labor no longer include appreciable numbers of young, native-born workers – and in most cases, natives haven’t been represented for a decade or more.  That is partly because there aren’t enough new, native-born entrants to the labor market, but also because of changing attitudes in our society toward manual jobs.  

Many immigrant-dependent firms have already tried various alternatives to hiring immigrants but they find no good substitutes.  Some businesses may be able to reduce their overall labor requirements through further mechanization, but this option is available mainly to certain types of agricultural employers – not to those in services, retail,  and construction.  

Are established immigrants and their offspring stuck in the kinds of dead-end, low-wage, manual jobs that are typically held by newly arrived immigrants?   Many of first-generation immigrants – particularly Latinos – do have limited occupational mobility.  But the data on subsequent generations are much more encouraging:  From the first to the second generation, there is considerable movement into white-collar occupations, and out of low-wage service, construction, and agricultural work.  

Even within the first generation, there is significant income improvement over time, as immigrants gain new skills, job seniority, and English proficiency.  Census data analyzed by the Public Policy Institute of California show that recently arrived immigrants in California have had the steepest decline in poverty since 1993.  There is still a large gap between immigrants and natives, but the gap has closed considerably in the last ten years.

The largest gaps in income, education, and occupational status are between Mexico-origin migrants and the native-born population.  But even for Mexicans, the big picture is one of progress.  There is not much change in occupational status among first-generation Mexican immigrants, but there is a big jump in the second and third generations. In terms of educational attainment, the children of Mexican immigrants are doing conspicuously better than their parents; they have much higher high-school graduation rates.  But the high-school drop-out rate is much too high, and college graduate rates are still low.  

A major reason why the second and third generations are doing better in terms of occupational and educational mobility is English proficiency.  The transition from Spanish to English-dominance usually occurs in just two generations rather than the three generations that it took European-origin immigrants who arrived in the early 20th Century.  These 21st Century immigrants don’t need the U.S. Congress to tell them that English is the national language.  They universally recognize that English competence is essential to their economic success in the U.S.– and to their children’s success.   

Another common misconception is that illegal immigrants are, for the most part, working “off the books” in the underground economy.  But all major studies of unauthorized Mexican immigrants completed in the last two decades have found majorities of them working for “mainstream,” formal-sector employers.  They get regular paychecks and have state and federal taxes deducted from their earnings.  

Among more than 700 Mexican immigrants interviewed by my research team in January-February of this year, after they had returned to their home town in the state of Yucatán, fewer than one-quarter had paid no federal income taxes during their most recent stay in the United States, while 75% had had taxes withheld from their pay, or filed a tax return, or paid taxes both by withholding and tax return.  That is clear evidence that these are not “underground” workers contributing nothing to public coffers.  While the states and localities that provide services to unauthorized immigrants are disproportionately impacted, this is a revenue-sharing problem that should be addressed through federally financed, immigration impact-assistance programs.

One final point about economic incorporation:  Mexicans and other first-generation immigrants tend to have extremely high labor-force participation rates. Illegal immigrants are the most fully employed, with 94% of the men in the work force – significantly higher than native-born Americans.  As economist David Card has observed: “These workers may be low-skilled, but they have incredibly high employment rates.”  A broad legalization program would increase the U.S.’ rate of return on these immigrant workers by incorporating them more fully and enhancing the human capital that they bring.


1 Testimony prepared for the House Judiciary Committee, Field Hearing on Immigration, San Diego, Calif., August 2, 2006.

2 These findings are reported in detail in Wayne A. Cornelius and Jessa M. Lewis, eds., Impacts of Border Enforcement on Mexican Migration: The View from Sending Communities (Boulder, Col.: Lynne Rienner Publishers and Center for Comparative Immigration Studies, UCSD, forthcoming 2006); and Wayne A. Cornelius, David Fitzgerald, and Pedro Lewin Fischer, eds., Mexican Migration to the United States: The View from a ‘New’ Sending Community (Boulder, Col.: Lynne Rienner Publishers and Center for Comparative Immigration Studies, UCSD, forthcoming 2007).