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I) Immigration Legislation of the 109th Congress (2005-2006)
II) Immigration Legislation
III) Immigration Statistics
IV) Composition of Immigrant Population
V) Contribution of immigrants to the US economy?
VI) Illegal Immigration and Border Security
VII) Suggested Readings

The number of foreign-born residents of the United States (37 million) is at its highest level in US history and constitutes a proportion of the US population (12.4%) not seen since the early 20th century.1 Of these immigrants to the US, approximately one-third are naturalized citizens, one-third are legal permanent residents, and one-third are illegal aliens. In response to increased immigration, political leaders on both sides of the aisle have called for reforms to US immigration policy. Proponents of immigration reform argue that high levels of immigration to the US have harmful consequences for both the US economy and society, reducing US labor wages, burdening government programs and US infrastructure, and creating insular communities that fail to integrate into American society and culture. To the contrary, immigration advocates contend that the American economy and society derives a net benefit from immigration, with foreign-born (often illegal) workers willing to take jobs at low-wages at a time when the supply of low-skilled American workers is on the decline. In the aftermath of the September 11th terrorist attacks, however, security concerns have figured prominently in the public debate over immigration reform and unauthorized immigration. In 2002, Congress shifted responsibility for immigration policy from the former Immigration and Naturalization Service (INS) to the Department of Homeland Security (DHS). A political consensus thus exists to halt illegal immigration and tightly control legal immigration.

This consensus breaks down, however, in the debate over specific proposals for reforming the US immigration system. A strategic divide exists over whether to enact incremental reforms (e.g., border security, employment verification, temporary worker programs) or comprehensive reforms of the US immigration system. In the latter, a sharp divide has emerged between those favoring a "pathway to citizenship"for the undocumented immigrants already in the U.S. and those advocating more punitive "enforcement"measures. The Bush administration has repeatedly called on Congress to pass comprehensive immigration reform, including a guest-worker program that would allow illegal immigrants to continue working in the US. President Bush, however, has been unable to secure the support of members of his own party in Congress, particularly conservative Republicans, who oppose the guest-worker program. With the 2008 presidential campaign in full swing, it is increasingly unlikely that Congress will be able to reconcile divergent positions pass immigration reform in the coming year.2

For a review of reform efforts in 2007, see Tara Magner, "Immigration Reform: Failure and Prospects,"Audit of Conventional Wisdom, MIT Center for International Studies, Sept. 2007.

    1. Historical Trends in Immigration to the US
    1. Immigration to the United States, 1820-2006

Figure 1: Immigration to the US, 1820-2006
Click to enlarge

Note: These data represent persons admitted for legal permanent residence during the twelve-month fiscal year ending in October of the year designated. The total for 1976 includes both the fiscal year and transitional quarter data.

Source: Derived from Table 1 in Office of Immigration Statistics, US Department of Homeland Security, Yearbook Of Immigration Statistics 2006 (Washington, DC: US Government Printing Office, 2007. Available at

  1. The US Immigrant Population

Figure 2: US Immigrant Population, 2000-2006
Click to enlarge

Source: Gordon H. Hanson, "The Economic Logic of Illegal Immigration,"CRS No. 26 (New York: Council on Foreign Relations, April 2007).

    1. Size of Foreign-Born Population as Percentage of Total US Population, 1850-2006

Figure 3: Size of Foreign-Born Population as Percentage of Total US Population, 1850-2006
Click to enlarge

Source: Migration Policy Institute, MPI Data Hub, Data derived from the 2006 American Community Survey, the 2000 data are from Census 2000 (see All other data are from Gibson, Campbell and Emily Lennon, US Census Bureau, Working Paper No. 29, Historical Census Statistics on the Foreign-Born Population of the United States: 1850 to 1990, US Government Printing Office, Washington, DC, 1999.

    1. Source Countries with the Largest Immigrant Populations in the US, 2006

Figure 4: Countries with the Largest Populations in the United States as Percentages of the Total Foreign-Born Population: 2006
Click to enlarge

Source: Migration Policy Institute, MPI Data Hub, Data are from US Bureau of the Census, 2006 American Community Survey.

II) Contribution of Immigrants to the US economy?

  1. Number of Foreign-born workers in the U.S. economy

Figure 5: Share of Foreign Born in the Total US Population and in the US Civilian Labor Force, 1970-2005
Click to enlarge

Note: Foreign born refers to people residing in the United States who were not United States citizens at birth. The foreign-born population includes immigrants, legal non-immigrants (e.g., refugees and persons on student or work visas), and persons illegally residing in the United States. The civilian labor force includes all civilians 16 years and over who were classified as employed or unemployed during the reference week of the survey or census.

Source: Migration Policy Institute, MPI Data Hub,

  1. Occupation of Employed Foreign-Born Workers

Figure 6: Percentage of Foreign-Born Wage and Salary Workers Age 16 and Older by Industry, 2003 and 2006
Click to enlarge

Source: Migration Information Source, Foreign-Born Wage and Salary Workers in the US Labor Force and Union,

  1. Immigration and the Rate of Employment

Figure 7: Immigration and the Rate of Employment, 1990-2005
Click to enlarge

Source: Source: Gordon H. Hanson, "The Economic Logic of Illegal Immigration,"CRS No. 26 (New York: Council on Foreign Relations, April 2007).

  1. Illegal Immigration and the US Economy
    • Approximately 7. 5 million undocumented immigrants are currently employed in the US economy (See Jeffrey S. Passell, "The Size and Characteristics of the Unauthorized Migrant Population in the U.S.: Estimates based on the March 2005 Current Population Survey,"Pew Hispanic Center (March 7, 2006). Available at
    • Pew Hispanic Center estimates that 24 percent of farm workers, 17 percent of cleaning workers, 14 percent of construction workers, and 12 percent of food preparation workers are undocumented, illegal immigrants. Overall, illegal immigrants constitute an estimated 4.9 percent of the U.S. workforce. (See Jeffrey S. Passell, "The Size and Characteristics of the Unauthorized Migrant Population in the U.S.: Estimates based on the March 2005 Current Population Survey,"Pew Hispanic Center (March 7, 2006). Available at
  2. Immigration and US Labor Wages
    • In an often cited research paper from the National Bureau of Economic Research, George Borjas and Lawrence Katz conclude that immigrant workers, specifically those from Mexico, has a downward pressure on wages for certain workers. See George Borjas and Lawrence Katz, "The Evolution of the Mexican-Born Workforce in the United States,"NBER Working Paper No. 11281 (April 2005). Available at

VI) Immigration and Border Security

A) Department of Homeland Security and Border Enforcement

    • Since 9/11, the Bush Administration has increased funding for border security and immigration enforcement by 159 percent, including emergency funding, from $4.8 billion in 2001 to $12.3 billion in 2008. See
    • The Bush administration has expanded the Border Patrol from approximately 9,000 agents in 2001 to more than 15,000 agents in 2008. See
    • The Department of Homeland Security (DHS) will complete 370 miles of pedestrian fencing along the US-Mexican border by the end of calendar year 2008. As of January 2008, DHS has completed a total of 165 miles of pedestrian fence along the US-Mexican border. See

B) Border Apprehensions, 1996-2005

    • In 2005, Department of Homeland Security apprehended an estimated 1.3 million illegal immigrants to the US. The vast majority of these apprehensions occurred near US borders shortly after an illegal entry. See Amy Wu, "Border Apprehensions: 2005,"Fact Sheet (November 2006). Available at
    • Border Apprehensions and Investigations, 1998 to 2005

    • Demographics of Border Patrol Apprehensions:

    1. Immigration and Terrorism
    • For a review of terrorist travel to the US, see Janice L. Kephart, "Immigration and Terrorism: Moving Beyond the 9/11 Staff Report on Terrorist Travel,"Center for Immigration Studies (September 2005). Available at
    • The Visa-Waiver Program: Prior to 1986, the US required visas for all foreigners visiting the US, with the exception of Canadians and Mexicans with border-crossing cards. In 1986, the US Congress passed a reciprocal visa-waiver program to allow citizens of certain favored nations, mostly in Europe, to enter the US for up to 90 days with a visa, and vice versa.
      • There are now 27 countries in the visa-waiver program: Andorra, Australia, Austria, Belgium, Brunei, Denmark, Finland, France, Germany, Iceland, Ireland, Italy, Japan, Liechtenstein, Luxembourg, Monaco, the Netherlands, New Zealand, Norway, Portugal, San Marino, Singapore, Slovenia, Spain, Sweden, Switzerland, and the United Kingdom.
      • In the aftermath of 9/11, the visa-waiver program came under criticism as an easy means for terrorists, particularly those with European passports, to enter the US. Zacarias Moussaoui, often referred to as the 20th hijacker,entered the U.S. before 9/11 on his French passport. Richard Reid, the ''shoe bomber,'' was able to board an airplane headed for the United States without a U.S. visa by showing his British passport. Ramsi Yusuf, one of the 1993 World Trade Center bombers, was able to enter the U.S. through visa waiver by using a counterfeit European passport.
      • In response to post-9//11 security concerns, Congress required with the Patriot Act of October 2003 for visa-waiver applicants to use machine-readable passports. New passports issued by visa-waiver countries are also required to be e-passports with computer chips for storing biometric information.
      • Critics charge that these new passport requirements fail to address the national security threat of visa waiver.

Suggested Reading

Peter Andreas, "Redrawing the Line: Borders and Security in the Twenty-first Century,"International Security 28:2 (Fall 2003): 78-111.

Peter Andreas, "The Escalation of U.S. Immigration Control in the Post-NAFTA Era,"Political Science Quarterly 113: 4 (1998-99): 591-613.

Faye Bowers, "U.S.-Mexican border as a terror risk,"The Christian Science Monitor (March 22, 2005).

Wayne A. Cornelius, "Death at the Border: Efficacy and Unintended Consequences of US Immigration Control Policy,"Population and Development Review 27:4 (Dec. 2001): 661-685.

G. H. Hanson, R. Robertson, A. Spilimbergo, "Does Border Enforcement Protect U.S. Workers from Illegal Immigration?" Review of Economics and Statistics, Vol.84, No. 1 (Feb. 2002), pp. 73-92.

Karen I. Leonard et al., (eds.), Immigrant Faiths: Transforming Religious Life in America. (New York: AltaMira, 2005).

Douglas S. Massey, Testimony before the U.S. Senate Judiciary Committee, October 18, 2005; see also his article, "The Wall that Keeps Illegal Workers In,"New York Times (April 4, 2006).

Jeffrey S. Passell, The Size and Characteristics of the Unauthorized Migrant Population in the U.S.: Estimates based on the March 2005 Current Population Survey (Washington, DC: Pew Hispanic Center, March 7, 2006), available at

John Tirman, ed., The Maze of Fear: Security and Migration after 9/11 (New York: New Press, 2004).

Ruth Ellen Wasem, U.S. Immigration Policy on Permanent Admissions (Washington, DC: Congressional Research Service, May 12, 2006). Available at

Myron Weiner, ed., International Migration and Security (Boulder: Westview, 1993).


1. Ruth Ellen Wasem, "Immigration Reform: Brief Synthesis of Issue," CRS Report For Congress (August 23, 2007). Available at

2. Jonathan Weisman and Jim VandeHei, "Immigration Debate is Shaped by '08 election," Washington Post (March 24, 2006).

Massachusetts Institute of Technology