According to the estimates by the Department of Homeland Security (DHS), some 11.4 million unauthorized immigrants were living in the United States in 2012. The Pew Research Center's unauthorized alien population estimate for 2012 was 11.2 million, which included some 8.1 million unauthorized workers in the U.S. civilian workforce. It is widely believed that most unauthorized aliens enter and remain in the United States in order to work. Six years ago, in 2009, DHS issued new guidance on immigration-related worksite enforcement—the enforcement of prohibitions on the employment of unauthorized aliens in the United States. In the words of DHS at the time, the 2009 guidance "reflects a renewed Department-wide focus targeting criminal aliens and employers who cultivate illegal workplaces by breaking the country's laws and knowingly hiring illegal workers." Under this guidance, promoting compliance also has taken on a larger role in DHS's worksite enforcements efforts. Questions arise as to how rigorous and effective DHS's worksite enforcement efforts are and have been in past years. The department maintains data on several measures that can be used to examine the performance of its worksite enforcement program. Enforcement activity by the Department of Labor (DOL) is also relevant to a discussion of federal efforts to address unauthorized employment. DOL, which is responsible for enforcing minimum wage, overtime pay, and related requirements, focuses a significant percentage of its enforcement resources on low-wage industries that employ large numbers of immigrant—and presumably large numbers of unauthorized—workers. Section 274A of the Immigration and Nationality Act (INA) prohibits employers from employing individuals who they know are not authorized to work. More specifically, the INA Section 274A provisions, sometimes referred to as employer sanctions, make it unlawful for an employer to knowingly hire, recruit or refer for a fee, or continue to employ an alien who is not authorized to be so employed. These provisions also make it unlawful for an employer to hire an individual for employment without examining documents to verify the new hire's identity and work eligibility, and completing and retaining verification forms, known as I-9 forms. These verification procedures, commonly referred to as the I-9 process or the I-9 requirements, are separate from the largely voluntary E-Verify electronic employment eligibility verification system, which is administered by DHS's U.S. Citizenship and Immigration Services (USCIS). Enforcement of the prohibitions on unauthorized employment in INA Section 274A—or worksite enforcement—has been the job of DHS's U.S. Immigration and Customs Enforcement (ICE) since 2003. Worksite enforcement is one component of ICE's responsibility to enforce federal immigration laws within the United States, known as interior enforcement. Employers violating the INA Section 274A prohibitions on unlawful employment may be subject to civil and/or criminal penalties. The federal government's approach to immigration-related worksite enforcement has changed over the years. In 1999, for example, the Immigration and Naturalization Service (INS) unveiled an interior enforcement strategy, which, as explained by an INS official at the time, gave priority in the area of worksite enforcement to two types of cases: (1) criminal employer cases, in which there was a pattern or practice of knowingly employing unauthorized workers, and (2) cases of employers who abused their workers and who violated multiple laws. In the aftermath of the September 11, 2001, terrorist attacks, interior enforcement priorities again shifted. Resources were redirected from traditional program areas, including worksite enforcement, to national security-related investigations, and the primary focus of worksite enforcement became removal of unauthorized workers from critical infrastructure facilities such as airports and military bases. Under the worksite enforcement guidance issued in 2009, homeland security remains a primary concern of ICE's worksite enforcement program. As described by ICE: "Investigations involving national security, public safety or those associated with our critical infrastructure and key resources sectors receive top priority." According to ICE, the agency also prioritizes criminally prosecuting employers who "utilize unauthorized workers as a business model," "mistreat their workers," or "engage in human smuggling or trafficking," among other violations. In recent years, ICE also has placed "increased emphasis on compliance and outreach" in conducting worksite enforcement. It has increased its use of inspections, or audits, of business owners' I-9 records (see above) to determine whether they are in compliance with employment eligibility verification laws and regulations. In addition, the agency promotes the ICE Mutual Agreement between Government and Employers (IMAGE) program as a way to reduce unauthorized employment. As discussed above, employers who violate INA prohibitions on the unlawful employment of aliens may be subject to civil and/or criminal penalties. Under INA Section 274A, civil money penalties can be imposed for failing to comply with the I-9 employment verification requirements and for knowingly hiring, recruiting or referring for a fee, or continuing to employ an unauthorized alien. A person or entity determined to have violated the I-9 requirements may be subject to a fine of not less than $110 and not more than $1,100 for each individual with respect to whom a violation occurred after September 29, 1999. A person or entity found to have engaged in hiring, recruiting, referring, or employing violations may be subject to a cease and desist order and to fines, as follows: for a first offense, not less than $275 and not more than $2,200 for each unauthorized alien with respect to whom the offense occurred before March 27, 2008, and not less than $375 and not more than $3,200 for each unauthorized alien with respect to whom the offense occurred on or after March 27, 2008; for a second offense, not less than $2,200 and not more than $5,500 for each unauthorized alien with respect to whom the offense occurred before March 27, 2008, and not less than $3,200 and not more than $6,500 for each unauthorized alien with respect to whom the offense occurred on or after March 27, 2008; and for more than two offenses, not less than $3,300 and not more than $11,000 for each unauthorized alien with respect to whom the third or later offense occurred before March 27, 2008, and not less than $4,300 and not more than $16,000 for each unauthorized alien with respect to whom the third or subsequent offense occurred on or after March 27, 2008. If ICE believes that an employer has committed a civil violation, the agency may issue the employer a Notice of Intent to Fine (NIF). A NIF may result in a Final Order for civil money penalties, a settlement, or a dismissal. Under INA Section 274A, employers convicted of having engaged in a pattern or practice of knowingly hiring or continuing to employ unauthorized aliens may face criminal fines and/or imprisonment. They may be fined not more than $3,000 for each unauthorized alien with respect to whom the violation occurred and/or imprisoned for not more than six months for the entire pattern or practice. Criminal investigations may result in employers and other individuals being charged with crimes other than unlawful employment, such as document fraud or harboring unauthorized aliens, and being subject to the relevant penalties for those violations. A variety of measures can be used to assess the performance of the DHS worksite enforcement program. Over the years, such assessments have been complicated by data reporting problems, the existence of conflicting data, and other issues. Unless otherwise noted, all data presented here were provided directly to the Congressional Research Service (CRS) by ICE. The paucity of comparable and/or reliable data for the pre-ICE worksite enforcement program, as indicated by ICE to CRS, however, limits the ability to place the recent performance data in historical context. As discussed above, INA Section 274A establishes civil penalties for violations of the I-9 requirements and for unlawful employment. Table 1 provides annual data on Final Orders for civil money penalties (also known as civil or administrative fines) for FY1999 through FY2014. It shows that after increasing between FY1999 and FY2000, the number of Final Orders and associated administrative fines decreased from FY2000 to FY2004. In FY2006, both measures equaled "0." Since FY2006, both measures have posted gains. Table 1 reflects changes over the years in the use of administrative fines as an enforcement tool. As noted above, the new DHS worksite enforcement strategy makes increased use of civil fines. In written testimony for a 2009 House hearing, Marcy Forman, then director of the ICE Office of Investigations, discussed ICE's renewed focus on civil fines: In crafting our worksite enforcement strategy, ICE has restructured the worksite administrative fine process to build a more vigorous program. ICE has established and distributed to all field offices guidance about the issuance of administrative fines and standardized criteria for the imposition of such fines. We expect that the increased use of the administrative fines process will result in meaningful penalties for those who engage in the employment of unauthorized workers. Despite the increases in recent years, however, the number of Final Orders for civil money penalties remains very low relative to the number of U.S. employers. Employers receiving Final Orders in FY2014, as shown in Table 1 , represent less than .02% of U.S. employers. Administrative and criminal arrests are other measures of worksite enforcement activity. Administrative arrests are for civil violations of the INA, such as being illegally present in the United States. Only a noncitizen can be the subject of an administrative arrest, which represents an initial step in the process of removing an alien from the United States. It seems reasonable to assume that most individuals arrested on administrative charges are non-managerial employees. Criminal arrests include arrests for illegal hiring as well as for identity theft, alien harboring, money laundering, and other criminal violations. Citizens and noncitizens alike can be the subject of criminal arrests, as can non-managerial employees, managerial employees, and employers. During each year from FY2003 to FY2008, as shown in Table 2 , the number of administrative and criminal arrests in worksite enforcement operations increased; some of the yearly changes, as from FY2005 to FY2006, were marked. In 2008 congressional testimony, then-DHS Secretary Michael Chertoff highlighted the number of administrative and criminal arrests in worksite enforcement operations in FY2007 as evidence of the progress being made by ICE on the worksite enforcement front. Between FY2008 and FY2009, as indicated in Table 2 , the number of individuals arrested on administrative and criminal charges plummeted. Since FY2011, there has been a steady decline in the number of both types of arrests. The reasons for the overall decreases in administrative and criminal arrests between FY2008 and FY2014 are unclear, but they may reflect, to some degree, ICE's stated renewed focus on employers. In his 2011 House testimony, then-ICE Deputy Director Kibble responded to concerns expressed by some Members of Congress about the diminished number of administrative arrests in worksite enforcement operations: The number of administrative arrests at worksites cannot, and should not, be considered in a vacuum. For the past two years, our worksite efforts have been part of a broader enforcement strategy that has seen the removal of more individuals from the United States than at any other time in the agency's history. ICE is apprehending, detaining, and removing an unprecedented number of individuals who are unlawfully present in the country—regardless of where they are apprehended. ICE worksite enforcement arrest statistics for FY2009 and FY2010 provided to CRS contain employment position titles for most individuals who were arrested on administrative or criminal charges. Of the 1,647 total worksite enforcement administrative arrests in FY2009, employment position information is available for 1,153 individuals. Non-managerial employees accounted for 1,112 of these 1,153 arrests (96%), while managerial employees with position titles that included owner, manager, and corporate official accounted for the remaining 41 arrests (4%). Of the 1,217 total administrative arrests in FY2010, employment position information is available for 897 individuals. Non-managerial employees accounted for 821 of these 897 arrests (92%), while managerial employees accounted for the remaining 76 arrests (8%). With respect to worksite enforcement criminal arrests, employment position information is available for 403 of the 444 individuals arrested on criminal charges in FY2009. These 403 individuals included 289 non-managerial employees (72%) and 114 managerial employees with position titles that included owner, manager, and corporate official (28%). Of the 448 individuals arrested on criminal charges in FY2010, employment position information is available for 385. Non-managerial employees accounted for 189 of these 385 arrests (49%), while managerial employees accounted for 196 criminal arrests (51%). Thus, while the number of overall criminal arrests in worksite enforcement operations was quite similar between FY2009 and FY2010, the number of managerial employees among the arrestees increased from 114 to 196. This increase, which is in line with ICE's stated focus in the worksite enforcement area on criminally investigating and prosecuting employers who knowingly employ unauthorized workers, follows a decline in criminal arrests among managerial employees between FY2008 and FY2009. The comparable number of managerial employee criminal arrests in FY2008 was 135, according to ICE. The representation of managerial employees among those criminally arrested varied in FY2012 and FY2013. For FY2012, as for FY2010, it seems that about half of the individuals criminally arrested in connection with worksite enforcement investigations were managerial employees. According to ICE, 240 of the 520 individuals arrested on criminal charges in FY2012 were owners, managers, supervisors, or human resources personnel. For FY2013, managerial employees accounted for about 40% of criminal arrests in connection with worksite enforcement investigations. ICE reports that 179 of the 452 individuals arrested on criminal charges in FY2013 were owners, managers, supervisors, or human resources personnel. Viewed more broadly, ICE administrative and criminal arrests in worksite enforcement operations represent a very small percentage of the potential population of violators. For example, Table 2 shows a high of 5,184 administrative arrests in worksite operations in FY2008. That year, according to the Pew Research Center, there were an estimated 8.3 million unauthorized aliens in the U.S. civilian labor force. With respect to criminal arrests, the potential population of employers and workers committing worksite-related criminal violations is not known. Table 3 provides data on criminal prosecutions related to worksite enforcement investigations for FY2005-FY2014. These data, which include employers and managerial and non-managerial employees, build on the criminal arrest data in Table 2 . As shown in Table 3 , the number of criminal indictments and criminal convictions rose steadily from FY2005 until FY2008. Both measures then fell markedly between FY2008 and FY2009 and have followed no consistent pattern since. It is difficult to draw direct conclusions from these data about the worksite enforcement program in any particular year. One reason for this is that there can be time lags between arrests, indictments, and convictions. Table 4 provides data on criminal fines and forfeitures related to worksite enforcement investigations that were imposed in FY2003-FY2014. ICE characterizes these data as follows: Criminal fines and forfeitures include fines imposed by a U.S. District Court as a result of a criminal conviction, seizures made by ICE and forfeited to the U.S. government, payments made to ICE in lieu of the seizure and forfeiture of real or personal property, and restitution payments made by an employer to their unauthorized alien employees as a result of labor law violations. As shown in Table 4 , worksite enforcement-related criminal fines and forfeitures have varied dramatically during the FY2003-FY2014 period, although they have remained well above the FY2003 level in all subsequent years. In light of the various types of fines and forfeitures (as indicated in the above description from ICE) and associated time lags, which presumably help explain the great annual variability, it may be that the total for any particular year is less significant than the fact that criminal fines and forfeitures were being pursued. In summary, the data presented here offer an available, but limited, means to examine the performance of ICE's worksite enforcement program. Some measures, namely Final Orders issued and administrative fines imposed, followed a downward trend after 2000 and then an upward trend after FY2006. Other measures, namely administrative arrests, criminal arrests, criminal indictments, and criminal convictions, registered increases from the initial years included here until FY2008, followed by significant decreases from FY2008 to FY2009. From FY2011 to FY2014, there was a steady decrease in both administrative and criminal arrests, while the yearly changes in criminal arrests and criminal indictments did not follow a consistent pattern. The FY2014 values for all four measures were below the FY2011 levels. The data on criminal fines and forfeitures imposed, the remaining measure, reveal no discernible pattern. More generally, the values of the various measures for the years shown seem quite small relative to the estimated size of the unauthorized workforce. While the authority to enforce the INA employer sanctions provisions rests with DHS, INA Section 274A does grant DOL the authority to review I-9 verification forms (see above). Under INA Section 274A(b)(3), employers must make completed I-9 forms available to DOL officers for inspection. DOL has separate authority to enforce federal labor laws, including the Fair Labor Standards Act (FLSA), which establishes minimum wage, overtime pay, youth employment, and other standards. The Wage and Hour Division (WHD) of the DOL Employment Standards Administration (ESA) administers and enforces the FLSA with respect to private sector workers, state and local government employees, and certain federal employees. Historically, DOL officials have been cautious about delving into questions of work authorization in their labor standards investigations because of concerns that it "might impede their ability to gain the trust of illegal aliens who may be the victims of labor violations and potential witnesses against employers." DOL and DHS signed a memorandum of understanding (MOU) on worksite enforcement in March 2011 that delineates the enforcement roles of each agency and the ways in which they will work together to further their respective missions. The MOU summarizes the importance of enforcing worksite-related labor and immigration laws, as follows: Effective enforcement of labor law is essential to ensure proper wages and working conditions for all covered workers regardless of immigration status. Effective enforcement of immigration law is essential to protect the employment rights of lawful U.S. workers, whether citizen or non-citizen, and to reduce the incentive for illegal migration to the United States. The MOU seeks to avoid conflicts in the worksite enforcement activities of DOL and DHS. As part of the MOU, ICE agrees not to conduct civil worksite enforcement activities at a worksite that is the subject of an existing DOL investigation of a labor dispute, except as specified. A labor dispute is defined in the MOU as a dispute between employees and managers/owners over employee rights, including the right to be paid the minimum wage, a promised or contracted wage, or overtime; the right to work in a safe workplace; and the right not to be subject to unlawful discrimination. Under the MOU, ICE can conduct worksite enforcement activities during a pending labor dispute in certain circumstances, such as when the Director of ICE determines that the enforcement activity is independently necessary to further an investigation concerning national security, the protection of critical infrastructure, or other federal crimes. ICE and DOL also agree as part of the MOU to work together to prevent manipulation of the enforcement process. To this end, ICE agrees to act to "thwart attempts by other parties to manipulate its worksite enforcement activities for illicit or improper purposes." DOL agrees to assist ICE in these efforts by sharing relevant information. While DOL's direct role in immigration-related worksite enforcement is quite limited, some maintain that the agency helps reduce unauthorized employment indirectly through its enforcement of labor laws. This argument is premised on the belief that many employers who employ unauthorized aliens also violate labor laws. A 2007 paper by Georgetown University's Institute for the Study of International Migration (ISIM) notes that employers have different propensities to hire unauthorized workers, and describes a category of employers that "knowingly hire[s] unauthorized workers to exploit their labor." According to the paper, "such employers may pay salaries in cash, failing to pay their share of social security taxes; and they may seek unauthorized workers because they are less likely to complain about ill treatment." Thus, with respect to unauthorized employment, enforcement of minimum wage, overtime, and other statutory requirements may serve as a means of reducing the economic incentives to hire unauthorized workers and thus result in decreased demand for these workers. Some other observers, such as former WHD Administrator Maria Echaveste, however, point out the limitations of using labor law enforcement to address unauthorized employment. They argue that many employers who hire unauthorized immigrants do not violate wage and hour laws. According to Echaveste: I know firsthand that many employers who comply with other labor standards still hire the undocumented. Many businesses pay the minimum wage and have barely tolerable working conditions because there are sufficient undocumented workers willing to accept those terms. If we care about low-income workers in this country, we need to create pressure to improve their economic condition by reducing the supply of unauthorized workers. To the extent that some employers of unauthorized aliens violate labor standards, WHD's compliance activities in low-wage industries may be particularly relevant to efforts to reduce unauthorized employment, as these industries may employ significant numbers of unauthorized aliens. Table 5 provides data on WHD investigations in nine low-wage industries in FY2014. That year, as indicated in Table 5 , WHD collected $79.1 million in back wages for FLSA overtime and minimum wage violations for about 109,000 workers. Top industries in terms of both the amount in back wages collected and the number of employees receiving back wages were restaurants and health care. Table 6 provides data on low-wage industry cases and back wage collections for FLSA overtime and minimum wage violations for FY2003-FY2014. As shown in Table 6 , the number of cases in low-wage industries generally decreased between FY2003 and FY2010 and then increased, reaching a high point in FY2013. This was followed by a drop between FY2013 and FY2014 that put the number of cases in FY2014 below the FY2003 level. Back wage collections and the number of employees receiving back wages registered greater overall increases than did the number of cases between FY2003 and FY2012, when both back wage measures reached high points. Despite subsequent decreases in both measures, the FY2013 and FY2014 values for both back wage collections and the number of employees receiving back wages were well above the FY2003 levels. More generally, though, when considered in the larger context of the potential number of employers in these low-wage industries that may be violating FLSA requirements with respect to unauthorized workers, or workers generally, the numbers in Table 5 and Table 6 , as in the ICE data tables, are relatively small. The data provided here on Final Orders, administrative fines, administrative and criminal arrests, criminal indictments and prosecutions, and criminal fines offer a way to assess DHS's worksite enforcement strategy over the years and in its current form. More broadly, it can be argued that the ultimate test for any approach to worksite enforcement by DHS or DOL is whether it helps reduce the size of the unauthorized labor force in the United States.

Summary: Under current Department of Homeland Security (DHS) guidance on immigration-related worksite enforcement, the agency uses available civil and administrative tools, including civil fines and debarment, to penalize and prevent unlawful employment. According to 2012 estimates, there are some 8.1 million unauthorized workers in the U.S. civilian labor force. DHS's U.S. Immigration and Customs Enforcement (ICE) is responsible for immigration-related worksite enforcement, or enforcement of the prohibitions on unauthorized employment in Section 274A of the Immigration and Nationality Act (INA). The INA Section 274A provisions, sometimes referred to as employer sanctions, make it unlawful for an employer to knowingly hire, recruit or refer for a fee, or continue to employ an alien who is not authorized to be so employed. Today, ICE's worksite enforcement program is focused primarily on cases that involve critical infrastructure facilities and cases involving employers who commit "egregious" violations of criminal statutes and engage in worker exploitation. Employers who violate INA prohibitions on the unlawful employment of aliens may be subject to civil monetary penalties and/or criminal penalties. Criminal investigations may result in defendants being charged with crimes beyond unlawful employment and being subject to the relevant penalties for those violations. Various measures are available to examine the performance of ICE's worksite enforcement program. They include Final Orders for civil monetary penalties, administrative fines, administrative arrests, criminal arrests, criminal indictments, criminal convictions, and criminal fines and forfeitures. In addition to examining annual changes and trends in the various performance measure data, these data can be considered in relation to the estimated size of the unauthorized workforce or the potential number of employers employing these workers. When considered in this context, ICE's worksite enforcement program can seem quite limited. Enforcement activity by the Department of Labor (DOL) is also relevant to a discussion of federal efforts to curtail unauthorized employment. DOL, which is responsible for enforcing minimum wage, overtime pay, and related requirements, focuses a significant percentage of its enforcement resources on low-wage industries that employ large numbers of immigrant—and presumably large numbers of unauthorized—workers.