Testimonyof
AlexNowrasteh
ImmigrationPolicyAnalyst
CatoInstitute
DecliningDeportationsandIncreasingCriminalAlienReleases–TheLawlessImmigration
PoliciesoftheObamaAdministration
Before
UnitedStatesSenateCommitteeontheJudiciary
May19,2016
ChairmanSessions,RankingMemberSchumer,anddistinguishedmembersofthe
Committee,Ithankyoufortheinvitationtoappearattoday’simportanthearing.IamAlex
Nowrasteh,immigrationpolicyanalystattheCatoInstitute,anon-profit,non-partisan
publicpolicyresearchinstitutelocatedhereinWashington,D.C.BeforeIbeginmy
testimony,Iwouldliketomakeclearthatmycommentsaresolelymyownanddonot
representanyofficialpositionsoftheCatoInstitute.Inaddition,outsideofmyinterestasa
citizenandtaxpayer,Ihavenodirectfinancialinterestinthesubjectmatterbeforethe
Committeetoday,nordoIrepresentanyentitiesthatdo.
Thistestimonywillpresenttheotherfactorsthatinfluencetheintensityofimmigration
enforcement,suchasunemployment,economicgrowth,violence,aswellasthedecisions
madebypolicymakersbothhereandabroad.Historicchangesinillegalimmigrant
apprehensions,intensificationsofinteriorenforcementfollowedbyrelaxations,the
ongoingdramaoftheUnaccompaniedAlienChildren(UAC),andotherpost-1965shiftsare
allinfluencedbytheseotherfactors.Duetotheirinfluence,manyimmigration
enforcementactionssince1965haveunintentionallyincreasedtheillegalimmigrant
populationlivingintheUnitedStates.
ICE’sInteriorImmigrationEnforcement
ImmigrationandCustomsEnforcement(ICE)isthelargestinvestigativedivisioninthe
DepartmentofHomelandSecurity(DHS)responsibleforenforcingfederalimmigration
lawsaspartofitsmission.
TheNumbers
ICE’sinteriorimmigrationenforcementpeakedwith237,941removalsin2009andhas
subsequentlydropped(seeTable1).1From2009through2015,ICEremovalsfromthe
interioroftheUnitedStatestotaledover1.17million.DuringtheyearsoftheGeorgeW.
Bushadministrationforwhichdataareavailable,atotalof555,164immigrantswere
deportedfromtheinterioroftheUnitedStates.Unfortunately,wedonothaveallofthe
dataforinteriorimmigrationenforcementduringtheBushadministration.Evencounting
1
alloftheremovalsfor2001and2002fromtheYearbookofImmigrationStatisticsas
interiorremovals,whichisalargeoverestimation,doesnotcomeclosetoovercomingthe
Obamaadministration’sinteriorremovalfigures.2ICEhasdeportedmoreimmigrantsfrom
theinterioroftheUnitedStatesduringtheObamaadministrationthanitorsimilar
agenciesdidduringtheBushadministrationnomatterhowyoumeasureit.
AnotherwayofviewingtheintensityofICEremovalsisasapercentageofthetotal
estimatedpopulationofillegalimmigrants.ICEremovalsasapercentageofallillegal
immigrantspeakedat2.12percentin2009(seeChart1).Forthefiveavailableyearsofthe
Bushadministration,anaverageof0.83percentoftheillegalimmigrantpopulationwere
deportedannuallywithalowpointof0.31percentin2003andahighpointof2.08percent
in2008.Evenifwegivecreditforthe2009removalpercentagetoPresidentBushbecause
ICEhadplannedforthatyear’soperationsin2008,hisannualaveragerisesto1.01
percent.RestrictingthecreditforinteriorremovalstoPresidentObama’sadministration
from2010onwardsproducesanaverageICEinteriorremovalrateof1.38percent.Inboth
situations,PresidentObama’sICEhasremovedmoreillegalimmigrantsasapercentageof
theentirepopulation.
Table1
InteriorICERemovals,IllegalImmigrantPopulation,andthePercentageofthatPopulation
RemovedbyICE
ICERemovalsfrom
IllegalImmigrant
PercentofPopulation
Interior
Population
RemovedfromInteriorbyICE
2003
30,468
9,750,000
0.31%
2004
49,577
10,100,000
0.49%
2005
56,332
10,600,000
0.53%
2006
75,268
11,100,000
0.68%
2007
108,749
12,200,000
0.89%
2008
234,770
11,300,000
2.08%
2009
237,941
11,250,000
2.12%
2010
229,235
11,400,000
2.01%
2011
223,755
11,500,000
1.95%
2012
180,970
11,200,000
1.62%
2013
133,551
11,250,000
1.19%
2014
102,224
11,300,000
0.90%
2015
69,478
11,300,000
0.61%
Sources:ImmigrationandCustomsEnforcement,MigrationPolicyInstitute,PewResearch
Center.
Year
2
Chart1
InteriorICERemovalsasaPercentofIllegalImmigrantPopulation
2.50%
2.08% 2.12%
2.00%
2.01%
1.95%
1.62%
1.50%
1.19%
1.00%
0.90%
0.89%
0.49% 0.53%
0.50%
0.68%
0.61%
0.31%
0.00%
2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015
PercentofAllIllegalImmigrantsDeportedfromInterior
Sources:ImmigrationandCustomsEnforcement,MigrationPolicyInstitute,PewResearch
Center.
Themajordifferencebetweenthetwoadministrationsisthetrajectoryofinterior
removals.ThenumberincreasedeveryyearoftheBushadministrationwhiletheybegan
fallingduringPresidentObama’sadministrationin2010.Asaresult,thepercentageofthe
illegalimmigrantpopulationremovedin2015andthetotalnumberaresimilartothoseof
2005and2006.Theydonotappeartobehistoricallylowfigurescomparedtointerior
immigrationenforcementinyearspriorto2005.
ExplanationforShiftingNumbers
Thereareseveralchangesinpolicyandotheractionsthatcanpotentiallyexplainthese
fluctuationsininteriorimmigrationenforcement.Since1976,severalmemorandahave
soughttofocusimmigrationenforcementonsomeclassesofindividualsandto
deemphasizeenforcementofothers.3Moreimportantly,everyHomelandSecurity
appropriationsbillsince2008hasrequiredtheDHSsecretaryto“prioritizethe
identificationandremovalofaliensconvictedofacrimebytheseverityofthatcrime.”4
TherefocusingofICE’simmigrationenforcementtoremovingconvictedcriminalsbetrays
aqualityoverquantityapproachtodeportationsthatcanexplainagoodportionofthis
decreaseinenforcement.5Anothershiftistheincreaseduseofremovalsforillegal
immigrantsapprehendedontheborderaspartoftheConsequenceDeliverySystem
strategyimplementedin2005andcarriedoutbybothICEandCustomsandBorder
Protection(CBP)incooperation.6
3
ThosearejusttwoexamplesofpolicyshiftsthataffectICE’sinteriorenforcement.Instead
ofrunningthroughalitanyofadditionalmemorandaandpolicychanges,Iwillattemptto
explaintheunderlyingfactorsthatpromptedthosechangesinthefirstplace.
PooreconomicconditionsintheUnitedStateshavelikelyhistoricallycaused
administrationsandagenciestointensifyimmigrationenforcementwhileimproving
economicconditionshavecausedarelaxationinsuchenforcement.Interiorimmigration
enforcementrampsupwheneconomicgrowthispoorandunemploymentishigh–as
happenedintheearly1950s,1987,1994,and2001.7TheGreatRecessionoflate2007to
2009wasprecededbyaweakeningeconomyandincludedafinancialandhousingcrisis.
Notcoincidentally,thesearetheyearswhenICE’sinteriorimmigrationenforcementefforts
weremosteffective–addingmoreevidencetothetheory.
EconomistsWilliamF.ShughartIII,RobertD.Tollison,andMwangiS.Kimenyifoundthat
immigrationlawsaremorestrictlyenforcedduringtimesofeconomiccontractionandless
stringentlyenforcedduringtimesofeconomicexpansion.8Addingmoreweighttothose
findings,economistsMichaelD.MakowskyandThomasStratmannfoundthatfrom1990to
2000,thenumberofimmigrationandI-9auditsandtheamountofdiscretionaryfines
leviedagainstfirmsforviolatingimmigrationlawsincreaseswithunemployment.9Interior
economicconditionsalsoaffectenforcementalongtheborder.EconomistsGordonH.
HansonandAntonioSpilimbergofoundthatwhenindustriesthatemploymanyillegal
immigrantsexpandrapidlythenevenbordercontrolrelaxestoallowmorein–atleast
fromtheearly1970suntilthelate1990s.10Ineachoneofthosesituations,immigration
enforcementdecreasesaftertheendofhighunemploymentandtheresumptionof
economicgrowth.
LackofIncentives
NewimmigrationenforcementtoolssuchasE-Verifyprovideanevenstarkerlessonin
incentives.Alabama,Arizona,Mississippi,andSouthCarolinamandateE-Verifyforallnew
hiresinordertopreventtheemploymentofillegalimmigrantsandtothusturnoffthejobs
magnet.EmployerslargelyignoreE-Verifyinthesestatesandofficialstherehavelittle
interestinenforcingit.11In2014,only56percentofthenewhiresinAlabama,57percent
ofthenewhiresinArizona,44percentofthenewhiresinMississippi,and54percentof
thenewhiresinSouthCarolinawereevenrunthroughE-Verifydespiteauniversal
mandateinallofthosestates.12E-Verifywillnotbeeffectiveonitsown,itmustbe
enforcedinordertoachieveitsgoalsanditisnotbeingenforcedinstateswhere
immigrationenforcementispoliticallypopular.Ifthegovernmentsofthosestatesdonot
wanttoenforceE-Verifythenitwillbeverydifficulttoenforceitinjurisdictionswherethe
programislesswellliked.
Turningoffthejobsmagnetisalsoverydifficultandlikelycounterproductive.According
toafigureknownastheplacepremium,themarginalMexicanworkercanincreasehisor
herwagesby253percentbysimplyimmigratingtotheUnitedStates.13Aneffective
immigrationenforcementtoolmustlowerthatgainenoughtodisincentivizehimfrom
4
attemptingtoworkintheUnitedStates.Fromthatstartingpoint,E-VerifyinArizona
loweredthewagegainforMexicanillegalimmigrantsfrom253percentto240percent.14
Althoughillegalimmigrantsalreadyfaceawagepenaltyrelativetosimilarlyskillednatives
duetotheI-9requirements,likelythemostsuccessfulillegalimmigrationdeterrence
programineffect,E-Verify’scontributionbarelyregisters.15
InteriorenforcementtoolslikeE-Verifycanonlyhaveanimpactifofficersshowupand
monitorworksitecompliance.TheObamaadministrationhasenforcedworksite
immigrationlawsmoreintenselythananyotherPresident.16ComparedtotheGeorgeW.
Bushadministration,theObamaadministrationhasissued5.1timesasmanyfinalorders,
15.5timesasmanyadministrationfines,8.3timesasmanyadministrativearrests,and
initiated7.6timesasmanycases.17TheBushadministrationdidrampupinterior
enforcementonworksiteswhentheeconomystartedtoslowatthebeginningofthe
housingpricedecline.EnforcementincreasedevenmorerapidlyduringtheGreat
Recessionandthenrelaxedafterwardastheeconomyimproved–withtheexceptionof
administrativefinesandfinalordersthathaveremainedhighthrough2014.Thispattern
ofenforcementandthenmoderaterelaxationispartiallyconsistentwiththeeconomic
theoriesthattracktheintensityofenforcementoneconomicconditions.
IfinteriorenforcementtoolslikeE-Verifyweretobeinitiallyeffectiveatexcludingillegal
immigrantsfromemploymentintheUnitedStatesthenthewagesinthoseoccupations
wheretheynolongworkwouldrise,whichwouldthenincreasethewagegainfrom
immigratingtotheUnitedStates,whichwouldthencompensateimmigrantswhoare
willingtorisktheillegalmove.Inthisway,interiorimmigrationenforcementtoolscould
increasethepowerofthejobsmagnetinthelongrun.
BorderEnforcement
TwobigeventshavehappenedoverrecentyearsalongtheSouthwestborder.Thefirstis
thecollapseofMexicanillegalimmigrationandthesecondistheriseofapprehensions
fromnationsOtherThanMexico(OTM)whoaremostlyCentralAmericans.Those
combinedfactshavedramaticallyreducedtheflowofillegalimmigrantsthathasinturn
reducedapprehensionsfromabout1.7millionin2000to337,117in2015,a79.9percent
decline.18Apprehensionfiguresfor2015wereamere60,000belowthesamenumber
apprehendedin1972.19
ThenumberofMexicanapprehensionspeakedin2000atjustover1.6millionandhas
sincefallenby88.5percentto188,122in2015(Table2).20Overthesametimeperiod,
OTMsincreasedfromabout39,555toabout148,995–a276.7percentincrease.In2014,
thenumberofMexicanapprehensionsdippedbelow50percentandwasovertakenby
OTMsforthefirsttime–althoughitlastedforonlyoneyear(Chart2).Theentiredecline
inapprehensionscanbeattributedtothecollapseofMexicanillegalimmigration.IfOTM
apprehensionshadremainedattheir2000levelwhiletheMexicanapprehensionsfellas
theyactuallydid,therewouldhavebeen110,000fewertotalapprehensionsin2015than
thereactuallywere.
5
Table2
TotalCBPApprehensions
Mexican
OTM
Mexican
OTM
Apprehensions
Apprehensions
Apprehensions
Apprehensions
(%)
(%)
1997 1,412,953
1,387,650
98.21%
25,303
1.79%
1998 1,555,776
1,522,918
97.89%
32,858
2.11%
1999 1,579,010
1,534,515
97.18%
44,495
2.82%
2000 1,676,438
1,636,883
97.64%
39,555
2.36%
2001 1,266,214
1,224,047
96.67%
42,167
3.33%
2002 955,310
917,993
96.09%
37,317
3.91%
2003 931,557
882,012
94.68%
49,545
5.32%
2004 1,160,395
1,085,006
93.50%
75,389
6.50%
2005 1,189,075
1,023,905
86.11%
165,170
13.89%
2006 1,089,092
981,066
90.08%
108,026
9.92%
2007 876,704
808,688
92.24%
68,016
7.76%
2008 723,825
661,766
91.43%
62,059
8.57%
2009 556,041
503,386
90.53%
52,655
9.47%
2010 463,382
404,365
87.26%
59,017
12.74%
2011 340,252
286,154
84.10%
54,098
15.90%
2012 364,768
265,755
72.86%
99,013
27.14%
2013 420,789
267,734
63.63%
153,055
36.37%
2014 486,651
229,178
47.09%
257,473
52.91%
2015 337,117
188,122
55.80%
148,995
44.20%
Sources:CustomsandBorderProtectionandtheCongressionalResearchService.
Year
All
Chart2
MexicansandOTMsasaPercentageofallCBPApprehensions
100.00%
90.00%
80.00%
70.00%
60.00%
50.00%
40.00%
30.00%
20.00%
10.00%
0.00%
1997199819992000200120022003200420052006200720082009201020112012201320142015
Mexicans
OTMs
Sources:CustomsandBorderProtectionandtheCongressionalResearchService.
6
TheincreaseinOTMs,especiallythoseapprehendedasUnaccompaniedAlienChildren
(UAC),hascausedmuchworry.Theirnumbersdidincreasebyover40,000from2010to
2014–a269percentboost.21Whilethatisasignificantincrease,theyappearallthelarger
andtakeupamoresignificantchunkofapprehensionsbecauseofthecollapseofMexican
apprehensions(Chart3).Forinstance,UACspeakedat68,631in2014at14percentofall
CBPapprehensionsthatyear–asubstantialfigure(Table3).22IfthatsamenumberofUAC
hadbeenapprehendedin2000,theywouldhavecomprisedamere3.6percentofall
apprehensions.
Chart3
MexicansandOTMsApprehendedbyCBP
1,800,000
1,600,000
1,400,000
1,200,000
1,000,000
800,000
600,000
400,000
200,000
0
Mexicans
OTMs
Sources:CustomsandBorderProtectionandtheCongressionalResearchService.
Table3
UnaccompaniedAlienChildrenasaPercentofAllApprehensions
Years
AllApprehensions
UAC
UAC(%)
2010
463,382
18,622
4.02%
2011
340,252
16,067
4.72%
2012
364,768
24,481
6.71%
2013
420,789
38,833
9.23%
2014
486,651
68,631
14.10%
2015
337,117
40,035
11.88%
Sources:CustomsandBorderProtectionandtheCongressionalResearch
Service.
BorderapprehensionshavehistoricallybeenresponsivetochangesinMexicanrealwages.
Forinstance,a10percentrelativedeclineinMexicanrealwagesisassociatedwitha6to8
7
percentincreaseinborderapprehensions.23ThisagainrevealsaparadoxforU.S.
immigrationenforcement.IfeffectiveimmigrationrestrictionsraiseU.S.wagesincertain
occupationsthenthebenefitsforanillegalimmigranttocomehereandworkarehigher
thanbefore,potentiallywipingoutthegainsinenforcement.24
ThoserelativeMexicanwages,however,havechangedinadifferentdirection.Mexicanper
capitaGDPadjustedforpurchasingpowerparity(PPP)ismuchhighertodaythanitwasin
1990(Chart4).TheUnitedStatespercapitaGDPPPPwasalmostfourtimesashighin
1990asitwasinMexicobutisnowjustbelow3.2timesashigh(Chart5).Therelatively
improvedMexicaneconomyismoreattractivetowould-beillegalimmigrants,
incentivizingmoreofthemtostayandthusdecreaseMexicanapprehensions.
ThoseGDPpercapitaPPPratiosarefarhigherforHonduras,ElSalvador,andGuatemala,
indicatingthattheincomegainsfrommovingtheUnitedStatearemuchhigherinthose
CentralAmericannationsthaninMexico(Chart6).Wecanexpectmoreillegal
immigrationfromthosenationsinthefuture.
Chart4
MexicanandCentralAmericanperCapitaGDP(PPP)
Mexico
Guatemala
8
ElSalvador
2014
2013
2012
2011
2010
2009
2008
2007
2006
2005
2004
2003
Honduras
Source:WorldBank.
2002
2001
2000
1999
1998
1997
1996
1995
1994
1993
1992
1991
1990
20000
18000
16000
14000
12000
10000
8000
6000
4000
2000
0
Chart5
RatioofAmericantoMexicanperCapitaGDP(PPP)
4.2
4
3.8
3.6
3.4
3.2
2014
2013
2012
2011
2010
2009
2008
2007
2006
2005
2004
2003
2002
2001
2000
1999
1998
1997
1996
1995
1994
1993
1992
1991
1990
3
Mexico
Source:WorldBank.
Chart6
RatioofRatioofAmericantoCentralAmericanperCapitaGDP(PPP)
14
12
10
8
6
4
2
0
Mexico
ElSalvador
Guatemala
Source:WorldBank.
9
Honduras
EconomistMichaelClemensattheCenterforGlobalDevelopmentfoundthatthenumberof
emigrantsdropsdramaticallywhensendingcountrypercapitaGDPPPPrisestobetween
$7000and$8000.25However,thatmeasurementtakesaccountofallnationsintheworld
anddoesnotcorrectfortransportationcosts.Mexico’sproximitytotheUnitedStates
greatlylowersthecostofimmigratinghereillegally,explainingtheacceleratedillegal
immigrationofMexicansevenafterpercapitaGDPPPPthereroseabove$8000inthemid1990s.26CentralAmericanscanalsoillegallyimmigratecheaplyduetotheirproximityso
weshouldnotexpectillegalimmigrationfromthosecountriestohaltoncetheirincome
risestothe$7000to$8000range.
TheageofmassillegalimmigrationfromMexicoislikelyoverformyriadreasonsother
thanborderorinteriorenforcement.However,illegalimmigrationfromCentralAmerican
nationswilllikelycontinueinthefutureduetotheirrelativepoverty,highratesofviolence,
andincreasedfamilyconnectionsintheUnitedStates.
CriminalAlienReleasesandSanctuaryCities
DHSSecretaryJehJohnsonreactedtothePresident’sexecutiveactionofNovember20,
2014bydiscontinuingSecureCommunities(S-COMM)andreplacingitwiththePriority
EnforcementProgram(PEP).ThenewPEPprioritizesICE’sremovalactionsbyallowing
themtoonlyseekatransferfromstateorlocalcustodytotheirownifthealienfallsunder
Priority1–threatstonationalsecurity,bordersecurity,andpublicsafety.27
Thereisapotentialtradeoffbetweenenforcingimmigrationlawsonthelocallevelandthe
abilityoflocalpolicetoenforcelocalandstatecriminallaws.28S-COMM’sphasedrollout
from2008toearly2013occurredinstagesunrelatedtolocalcrime,thusprovidingan
opportunitytouseadifference-in-differencestatisticalapproachtounderstandhowthe
programaffectedlocalcrimerates.S-COMMhadzeroeffectonlocalcrimeratesonewayor
theother29anditdidnotresultinincreasedpolicebrutalityassomeopponentsfeared.30
Asapolicytooltoincreasepublicsafetythroughtargetedimmigrationenforcement,SCOMMhaszeromeasurableeffectoncrimerates.
In2015,ICEreleased19,723criminalalienspendingremovalproceedings.Two-thirdsof
thosereleaseswerelegallyrequiredratherthantheresultofICE’suseofdiscretion.ICE’s
custodydecisionsmaybesubjecttoreviewbytheDOJ’sExecutiveOfficeofImmigration
Review(EOIR).SeveralSupremeCourtcaseshavealsoplacedlimitsonICE’sabilityto
detainremovableindividuals.31
UnaccompaniedAlienChildren
The2014surgeinUnaccompaniedAlienChildren(UAC)producedfewertotaljuvenile
apprehensionsthanintheyears2004and2005andslightlymorethanthenumber
apprehendedin2006(Table4).32ThesubcategoryofUAChascertainlysurgedinthese
yearsbutthetotalnumberofjuvenileapprehensionsisnotoutoftheordinary.Duetothe
declineinallapprehensions,juvenileapprehensionsareamuchlargerproportionofall
apprehensions.
10
Table4
AllJuvenileandUACApprehensions
Year
AllJuvenileApprehensions
UAC
2001
97,954
NA
2002
86,433
NA
2003
86,606
NA
2004
109,285
NA
2005
114,222
NA
2006
101,778
NA
2007
77,778
NA
2008
59,578
8,041
2009
40,461
19,668
2010
31,291
18,634
2011
23,089
16,056
2012
31,029
24,481
2013
47,397
38,833
2014
107,613
68,631
2015
62,167
40,035
Source:UnitedStatesBorderPatrol.
U.S.governmentpolicydidnotlikelycausetheUACsurge.Thetwogovernmentpolicies
mostcommonlycreditedwithstartedthesurgeweretheTraffickingVictimsProtection
ReauthorizationActof2008(TVPRA)andPresidentObama’sJune15,2012announcement
ofDeferredActionforChildhoodArrivals(DACA)thatcouldhavesignaledanamnestythat
UACcouldtakeadvantageof.TheTVPRAcodifiedprocedurescreatedinthe1990sforthe
returnofMexicanUACwithoutacourthearingunlesstheysaidtheyweretraffickedorthat
theyfearedpersecution.CentralAmericanUACweregrantedacourthearingand,priorto
thesurgein2014,werereleasedtotheirfamiliesintheUnitedStates.
DACAlikelydidn’tinfluencethesurgeofUACin2014forseveralreasons.First,the
increaseinUACwasalreadyunderwaybyJune15thwhenPresidentObamaannounced
11
DACA.SinceFebruaryofthatyear,themonthlyUAChadbeenabove2000thatprompted
thenTexasGovernorRickPerrytowritealettertoPresidentObamacomplainingaboutthe
situation.33PresidentObamaannouncedDACAmorethanamonthafterreceivedGovernor
Perry’sletter.
Second,DACAdidnotsetoffarushfortheborder.34IttookninemoremonthsafterDACA
wasannouncedforthenumberofUACtoriseabove4000andanothertwoyearsbeforeit
peakedinJune2014atover10,000(Chart7).35Third,DACAwouldnotapplytotheseUAC
becausetheyhavenotresidedintheUnitedStatessinceJune15,2007.36
Chart7
MonthlyUACandDACA
Source:CustomsandBorderProtectionandtheNiskanenCenter.
ThereareotherexplanationsthathelpexplainthesurgeofUAC.Oneisthatviolencein
Honduras,Guatemala,andElSalvadorarepushingthesechildrenouttowardtheUnited
States.Thehomicideratestherearehighandgangviolenceistargetingtheyoung(Chart
8).
12
Chart8
HomicideRatesper100,000
100
90
80
70
60
50
40
30
20
10
0
20002001200220032004200520062007200820092010201120122013
Mexico
Guatemala
Honduras
ElSalvador
Source:UnitedNationsOfficeonDrugsandCrime.
ThesecondpotentialexplanationisthattheUACsurgeisaresultoffamilyreunification.
DuringtheGreatRecession,thestockofCentralAmericanillegalimmigrantsactually
increasedwhilethenumberofMexicansdecreased.37ThesurgeofUACyearslateris
merelythereunificationpartofthatinitialillegalimmigration.Thirty-sixpercentofall
unaccompaniedchildrensurveyedpriorto2014hadatleastoneparentalreadyinthe
UnitedStatesandmanymentioned“familyreunification”asareasonforcoming.38This
surveylikelyundercountsthefamilytiesbetweentheUACandtheirU.S.-basedfamily
becauseitexcludesextendedfamilyconnections.Aunts,uncles,andcousinsalsoprovidea
bridgeforUACtoliveintheUnitedStates.ManyoftheUACarebeingreunitedwiththeir
familymembersintheUnitedStateseventhoughmanyofthemarecurrentlyworkingand
livinghereillegally.39
ThethirdpotentialexplanationisthattheMexicangovernmentunintentionallycausedthis
surgebysubstantiallyliberalizingitsimmigrationlaws.In2011,theMexicanlegislature
passedtheMigratoryActthatwentintoeffectonNovember1,2012.Thislawreplacedthe
olderandharsherGeneralLawofPopulationthatregulatedimmigration.TheMigratory
Actreducedthepunishmentforillegalentry,guaranteedtheequaltreatmentofmigrants
andMexicannationalsunderthelaw,establishedfamilyunityasanimportantprincipleof
Mexicanimmigrationlaw,createdofficestoprotectmigrantrightsandtoinvestigate
crimescommittedagainstthem,simplifiedentranceandresidencerequirements,
establishedapointssystemforthosewhoapplyforresidency,startedaguestworkervisa
programforGuatemalans,andcreateda3dayregionalvisitorsvisafortouristsfrom
neighboringcountries.40TheUACweresurgingtorecordnumberswithinfivemonthsof
thenewMexicanlawgoingintoeffect.
13
RelatedtotheMexicanliberalization,ElSalvador,Honduras,Guatemala,andNicaragua
signedabordercontrolagreementin2006thatcreatedacommonpassportand
obliteratedbordercontrolsandmovementrestrictionsbetweenthosefourcountries.
LiberalizedMexicanandCentralAmericanimmigrationlawsandbordercontrolslikely
playedalargeroleinloweringthecostofmigratingtotheUnitedStates.41
BorderEnforcement,LegalMigration,andIllegalImmigration
Theageofmodernillegalimmigrationbeganin1965whenthefederalgovernment
cancelledtheBraceroguestworkervisaprogramforMexicanfarmworkersandimposed
numericalquotasonWesternHemispherecountriesforthefirsttime.Bothactionslimited
thelegalmigrationopportunitiesforlower-skilledMexicans.Sincethentheborderpatrol’s
staffhasgrownover14foldwhilethesizeoftheillegalimmigrantpopulationpeakedat
12.2millionin2007beforedroppingto11.3millionin2014.42Thenumberof
apprehensionsperborderpatrolagentpeakedat953in1954andhasdippedto16.6in
2015,whichapproachesthoseseenduringtheheydayoftheBraceroProgramandduring
WorldWarII(Chart9).
Chart9
CBPApprehensionsperBorderPatrolAgent
1200
1000
800
600
400
200
0
ApprehensionsPerAgent
Source:DepartmentofHomelandSecurity.
TheBraceroProgramallowedinalmostfivemillionMexicanworkerstolegallyworkon
Americanfarmsfrom1942to1964.Theprogramunderwentseveralreformsduringits
existencesothatbythemid-1950sworkingonaBracerovisawaseasierthandoingso
illegally.Importantly,hiringaBracerowasalsoeasierthanhiringanillegalworker.Asa
result,theflowofMexicanillegalimmigrationreducedbyupwardsof90percentduring
the1950sevenasthenumberofborderpatrolofficersremainedaboutthesame.
14
CongressendedtheBraceroProgramin1964andtheImmigrationActof1965imposed
quotasonMexicansforthefirsttime.Thoserestrictionsonlegalmigrationopportunities
createdalargeblackmarketthatthrivedafter1965.TheH-2visaprogramforlowerskilledworkerscouldnotlegallysupplyAmericandemandforMexicanlaborers.After
1965,borderpatrolapprehensionsskyrocketedasthenumberoflegalmigrantvisas
shrankandstayedsmall(Chart10).
Chart10
LowSkilledTemporaryWorkerVisasandBorderPatrolApprehensions,1942-2013
1,800,000
1,600,000
1,400,000
1,200,000
1,000,000
800,000
600,000
400,000
200,000
0
1942
1949
1956
1963
1970
1977
BorderPatrolApprehensions(LeY)
1984
1991
1998
2005
2012
LowSkilledVisas(Right)
Sources:DepartmentofHomelandSecurity,CustomsandBorderProtection,Citizenshipand
ImmigrationServices.
From1965to1986,about28millionillegalMexicanimmigrantsenteredtheUnitedStates
whowerethenoffsetby23.4milliondepartures,yieldinganetincreaseofonly4.6
million.43LiketheBraceroProgram,theillegalcrossborderflowwasmostlytemporary.
From1965to1986,thelikelihoodofanillegalimmigrantreturningtoMexicoafterhisfirst
tripvariedbetween55to60percentwhilethelikelihoodofreturningfromasecondtrip
was80percent.44
Thepassageofthe1986ImmigrationReformandControlActlegalizedmanyofthe
unauthorizedMexicansbutalsointerruptedthetraditionaltemporaryworkerflowby
boostingbordersecurity.Asaresult,aMexicanillegalimmigrant’sprobabilityofreturning
toMexicoplummeted.45Subsequentincreasesinborderenforcementfurtherreducedthat
probabilityasthepriceofsmugglingintotheUnitedStateslikelyroseinresponse.46
Accordingtooneestimate,a10percentincreaseinenforcementhoursresultsina2.5
percentincreaseinthesmugglingprice.47Eventhoughsmugglingpricesandenforcement
15
increasedalongtheborder,thereisanemergingconsensusthatmoresecuritydidlittleto
reduceillegalimmigrationtotheUnitedStates.48Highcoststoenterincreasedthelength
ofstayandincreasedthecostofleavingbylimitingreturnoptions.
Evenifimmigrationenforcementalongtheborderdidlittletokeepoutillegalimmigrants,
itdidproducemanyunanticipatedconsequences.Thefirstisthatitlockedmany
unauthorizedmigrantsinsideoftheUnitedStates.49Iftheworkercannotmovebackand
forththenhisfamilywillcomenorth–andthatisexactlywhathashappenedsince1986.
NewbordercontrolstrategiesliketheConsequenceDeliverySystemandothersare
ineffectiveatdeterringillegalimmigrationanddomoretolocktheminsideoftheUnited
Statesoncetheyarehere.50Thesecondeffectwasthatincreasedenforcementredirected
theflowofillegalimmigrantstowarddifferentsectorsoftheborder,primarilyArizona,
thatfunneledthemtodifferentpartsoftheUnitedStates.51ToquoteDouglasMasseyof
PrincetonUniversity,“theunprecedentedmilitarizationoftheMexico-U.S.bordernotonly
failedinitsattempttoreduceundocumentedmigrationbutbackfiredbyincreasingthe
rateofundocumentedpopulationgrowthandturningwhathadbeenacircularflowof
maleworkersgoingtothreestatesintoasettledpopulationoffamilieslivingin50
states.”52
Asaresponsetoexpandedbordersecurity,thosewhointendtoimmigrateillegallyare
increasinglyoverstayingtheirnonimmigrantvisas.Accordingtothemostrecentestimate
byRobertWarrenandDonaldKerwin,58percentoftotalillegalimmigrantarrivalsin2012
wereoverstaysupfromanestimated26percentinthemid-1980s.53
Increasedborderenforcementandfundinginevitablyledtomoreapprehensionsbecause
theadditionalresourcescouldalwaysbeusedtoapprehendmoreillegalmigrants.This
cyclewasshatteredbytheGreatRecession.54Immigrationenforcementdidnotendthe
ageofMexicanillegalimmigration,afinancialandhousingcrisisdid.Alargemigrant
workerprogramlikeBracerocouldchannelthevastmajorityoffuturewould-beillegal
immigrants,likelytocomefromCentralAmerica,intothelegalmarket.Itworkedduring
theearlydaysoftheBraceroProgramanditcoulddosoagain.55
Conclusion
Manyofthegovernment’sactionstohaltillegalimmigrationareeitherineffectiveor
counterproductive.Theeconomyandadministrativeincentivespredictablydrivecyclesof
harshimmigrationenforcementandperiodsofrelativelaxity.Newenforcementtoolslike
E-Everifywillbesubjecttothesesameconstraints.
IllegalimmigrationfromMexicohascollapsedduetoeconomicchangesinthatcountryand
theUnitedStates,notbecauseofenforcement.However,illegalimmigrationhasincreased
fromCentralAmericannationsduetonumerousfactorsinadditiontotheusualeconomic
draw.IfborderenforcementwastheexplanationforthedeclineinMexicanillegal
immigrationthenweshouldnotalsobeseeingariseinCentralAmericanillegal
immigration.IllegalimmigrationfromCentralAmericawilleventuallydeclinewhentheir
incomesrisecomparedtothoseofAmericansandviolencedeclines.
16
Theformidablestateofcurrentimmigrationenforcement,muchofitexpandedandmore
enforcedbytheObamaadministration,certainlydeterssomeillegalimmigrantsfrom
enteringtheUnitedStatesbutitalsolocksmanyinsidewhowouldotherwisehaveleft.56
Insteadofalargepopulationflowingbackandforthacrosstheborderbasedonsupplyand
demand,thestockofillegalimmigrantsismorepermanentandsettled.Accordingto
estimatesbyProfessorDouglasMasseyatPrinceton,therewouldbe5.3millionfewer
illegalimmigrantsintheUnitedStatesin2011ifimmigrationenforcementwasatitspre1986level.57
1DepartmentofHomelandSecurity,“ICEEnforcementRemovalOperationsReport,FiscalYear2015,”
December22,2015,p.8.,
https://www.ice.gov/sites/default/files/documents/Report/2016/fy2015removalStats.pdf.
2
DepartmentofHomelandSecurity,“YearbookofImmigrationStatistic:2014,”Table39,
https://www.dhs.gov/yearbook-immigration-statistics-2014-enforcement-actions.
3Theselistedmemorandaareavailable,seeU.S.ImmigrationandCustomsEnforcement(ICE)Assistant
SecretaryJohnMorton,memorandumtoICEFieldOfficeDirectors,SpecialAgentsinCharge,andChief
Counsel,“ExercisingProsecutorialDiscretionConsistentwiththeCivilImmigrationEnforcementPrioritiesof
theAgencyfortheApprehension,Detention,andRemovalofAliens,”June17,2011,
https://www.ice.gov/doclib/secure-communities/pdf/prosecutorial-discretion-memo.pdf.
4
TheConsolidatedAppropriationsActof2016(H.R.2029)isthemostrecentversionofthis,
https://www.congress.gov/bill/114th-congress/house-bill/2029/text.
5TestimonyofMarcR.Rosenblum,DeputyDirector,MigrationPolicyInstitute,beforetheSenateCommittee
ontheJudiciary:“OversightoftheAdministration’sCriminalAlienRemovalPolicies,”
http://www.migrationpolicy.org/research/senate-judiciary-testimony-immigration-enforcement-prioritiesand-use-prosecutorial.
6 TestimonyofMichaelJ.Fisher,Chief,U.S.BorderPatrol,U.S.CustomsandBorderProtection,beforethe
HouseCommitteeonHomelandSecurity,SubcommitteeonBorderandMaritimeSecurity:"Does
AdministrativeAmnestyHarmourEffortstoGainandMaintainOperationalControloftheBorder?"
https://www.dhs.gov/news/2011/10/04/written-testimony-cbp-house-homeland-security-subcommitteeborder-and-maritime.
7GordonH.Hanson,“TheGovernanceofMigrationPolicy,”UnitedNationsDevelopmentProgramme,
WorkingPaper2009/02,p.21http://hdr.undp.org/sites/default/files/hdrp_2009_02_rev.pdf,GordonH.
HansonHanson,“IllegalMigrationfromMexicototheUnitedStates,”JournalofEconomicLiterature,44
(2006):869-924,andWilliamF.ShughartII,RobertD.Tollison,andMwangiS.Kimenyi,“ThePolitical
EconomicofImmigrationRestrictions,”YaleJournalonRegulation4,1(Fall1986):79-97.
8WilliamF.ShughartII,RobertD.Tollison,andMwangiS.Kimenyi,“ThePoliticalEconomicofImmigration
Restrictions,”YaleJournalonRegulation4,1(Fall1986):79-97.
9MichaelD.MakowskyandThomasStratmann,“Politics,Unemployment,andtheEnforcementof
ImmigrationLaw,”PublicChoice160,1(2014):131-153.
10GordonH.HansonandAntonioSpilimbergo,“PoliticalEconomy,SectoralShocks,andBorderEnforcement,”
TheCanadianJournalofEconomics34,3(2001):612-638.
11AlexNowrastehandJimHarper,“CheckingE-Verify:TheCostsandConsequencesofaNationalWorker
ScreeningMandate,”CatoInstitutePolicyAnalysis775,July7,2015,p.8,
http://object.cato.org/sites/cato.org/files/pubs/pdf/pa775_1.pdf.
12AlexNowrasteh,“EmployersIgnoreE-Verify,”CatoAtLiberty,September1,2015,
http://www.cato.org/blog/employers-ignore-e-verify.
13MichaelClemens,ClaudioMontenegro,andLantPritchett,“ThePlacePremium:WageDifferencefor
IdenticalWorkersacrosstheU.S.Border,”CenterforGlobalDevelopmentWorkingPaperNumber148,July
2008,p.11,http://www.cgdev.org/sites/default/files/16352_file_CMP_place_premium_148.pdf.
17
14AlexNowrastehandJimHarper,“CheckingE-Verify:TheCostsandConsequencesofaNationalWorker
ScreeningMandate,”CatoInstitutePolicyAnalysis775,July7,2015,p.11,
http://object.cato.org/sites/cato.org/files/pubs/pdf/pa775_1.pdf.
15DouglasS.Massey,JorgeDurand,andNolanJ.Malone,BeyondSmokeandMirrors:MexicanImmigrationin
anEraofEconomicIntegration(NewYork:RussellSageFoundation,2002):118-121.
16
AndorraBruno,“Immigration-RelatedWorksiteEnforcement:PerformanceMeasures,”CongressionalResearch
Service,June23,2015.
17
Ibid.
18UnitedStatesBorderPatrolApprehensionsDatabyFiscalYear,
https://www.cbp.gov/sites/default/files/documents/BP%20Total%20Apps,%20Mexico,%20OTM%20FY20
00-FY2015.pdf.
19Ibid.
20Ibid.
21UnitedStatesBorderPatrol,TotalUnaccompaniedAlienChildren,
https://www.cbp.gov/sites/default/files/documents/BP%20Total%20Monthly%20UACs%20by%20Sector.
%2C%20FY10-FY16TD-Jan.pdf
22Ibid.
23GordonH.HansonandAntonioSpilimbergo,“IllegalImmigration,BorderEnforcement,andRelativeWages:
EvidencefromApprehensionsattheU.S.-MexicoBorder,”AmericanEconomicReview89,5(1999):1337-57.
24Forviewingtheemploymentrateforillegalimmigrantmenat85percentin2014comparedto74percent
fornative-bornmen,seeGeorgeJ.Borjas,“TheLaborSupplyofUndocumentedImmigrants,”NBERWorking
PaperNo.22102,March2016,http://www.nber.org/papers/w22102.pdf.
25MichaelClemens,“DoesDevelopmentReduceMigration,”CenterforGlobalDevelopmentWorkingPaper
359,March2014,p.35,http://www.cgdev.org/sites/default/files/does-development-reducemigration_final_0.pdf.
26Havocscope,“PricesChargedbyHumanSmugglers,”http://www.havocscope.com/black-marketprices/human-smuggling-fees/.
27WilliamA.KandelandLisaSeghetti,“SanctuaryJurisdictionsandCriminalAliens:InBrief,”Congressional
ResearchService,October20,2015,p.4,https://www.fas.org/sgp/crs/homesec/R44118.pdf,
28DavidS.Kirk,AndrewV.Papachristos,JeffreyFagan,andTomR.Tyler,“TheParadoxofLawEnforcement
inImmigrantCommunities:DoesToughImmigrationEnforcementUnderminePublicSafety?”TheAnnalsof
theAmericanAcademyofPoliticalandSocialScience641,1(2012):79-98.
29ThomasJ.MilesandAdamB.Cox,“DoesImmigrationEnforcementReduceCrime?EvidencefromSecure
Communities,”JournalofLawandEconomics57,4(2014):937-973.
30ElinaTreyger,AaronChalfin,andCharlesLoeffler,“ImmigrationEnforcement,Policing,andCrime:
EvidencefromtheSecureCommunitiesProgram,”CriminologyandPublicPolicy13,2(2014):285-322.
31WrittenTestimonyofICEDirectorSarahSaldanaforaHouseCommitteeonOversightandGovernment
reformhearingtitled“CriminalAliensReleasedbytheDepartmentofHomelandSecurity,”
https://www.dhs.gov/news/2016/04/28/written-testimony-ice-director-house-committee-oversight-andgovernment-reform. 32
UnitedStatesBorderPatrol,SectorProfile2015,
https://www.cbp.gov/sites/default/files/documents/USBP%20Stats%20FY2015%20sector%20profile.pdfand
33SeanCollinsWalsh,“PerryBlastsObamaOverRiseinIllegalImmigrantChildrenEnteringU.S.onTheir
Own,”TheDallasMorningNews,May7,2012,
http://www.dallasnews.com/news/politics/headlines/20120507-perry-blasts-obama-over-rise-in-illegalimmigrant-children-entering-u.s.-on-their-own.ece.
34DavidBier,“ExaminingtheUAC-DACALink:NewDataShowChildMigrantCrisisBeganBeforeDACA,”
NiskanenCenter,February9,2015,http://niskanencenter.org/wp-content/uploads/2015/02/Examiningthe-UAC-DACA-Link2.pdf.
35UnitedStatesBorderPatrol,TotalUnaccompaniedAlienChildren,
https://www.cbp.gov/sites/default/files/documents/BP%20Total%20Monthly%20UACs%20by%20Sector.
%2C%20FY10-FY16TD-Jan.pdfandDavidBier,“ExaminingtheUAC-DACALink:NewDataShowChild
18
MigrantCrisisBeganBeforeDACA,”NiskanenCenter,February9,2015,http://niskanencenter.org/wpcontent/uploads/2015/02/Examining-the-UAC-DACA-Link2.pdf.
36UnitedStatesCitizenshipandImmigrationServices,ConsiderationofDeferredActionforChildhoodArrival
(DACA),https://www.uscis.gov/humanitarian/consideration-deferred-action-childhood-arrivalsdaca#guidelines.
37BryanBakerandNancyRytina,“EstimatesoftheUnauthorizedImmigrantPopulationResidinginthe
UnitedStates:January2012,”DepartmentofHomelandSecurityPopulationEstimates,March2013,
https://www.dhs.gov/sites/default/files/publications/ois_ill_pe_2012_2.pdfandMichaelHoefer,Nancy
Rytina,andBryanC.Baker,“EstimatesoftheUnauthorizedImmigrantPopulationResidingintheUnited
States:January2007,”DepartmentofHomelandSecurityPopulationEstimates,September2008,
https://www.dhs.gov/sites/default/files/publications/ois_ill_pe_2007.pdf.
38UnitedNationsHighCommissionerforRefugees,“ChildrenontheRun,”
http://www.unhcrwashington.org/sites/default/files/1_UAC_Children%20on%20the%20Run_Full%20Repo
rt.pdf.
39
AmyTaxin,“ImmigrantKidsSenttoAdultsLackingStatus,”AssociatedPress,April19,2016,
http://bigstory.ap.org/article/40acc163f5d245ce940e7571d0f54bd4/immigrant-kids-placed-adults-who-are-usillegally.
40AlexNowrasteh,“MexicanImmigrationPolicyLowerstheCostofCentralAmericanMigrationtotheUS,”
CatoAtLiberty,July17,2014,http://www.cato.org/blog/mexican-immigration-policy-lowers-cost-centralamerican-migration-us.
41Ibid.
42“U.S.UnauthorizedImmigrantPopulation,1990-2014,”PewResearchCenter,
http://www.pewhispanic.org/2016/04/19/statistical-portrait-of-the-foreign-born-population-in-the-unitedstates-key-charts/#2013-fb-unauthorized-line.
43DouglasS.MasseyandAudreySinger,“NewEstimatesofUndocumentedMexicanMigrationandthe
ProbabilityofApprehension,”Demography32,2(1995):203-213.
44DoulasS.Massey,“ChainReaction:TheCausesandConsequencesofAmerica’sWaronImmigrants,”IZA
JulianSimonLectureSeries,(2011):17,http://www.iza.org/conference_files/amm2011/massey_d1244.pdf.
45Ibid.29.
46ChristinaGathmann,“EffectsofEnforcementonIllegalMarkets:EvidencefromMigrantSmugglingalongthe
SouthwesternBorder,”JournalofPublicEconomics92,10-11(2008):1926-1941.
47BryanRoberts,GordonHanson,DerekhCornwell,andScottBorger,“AnAnalysisofMigrantSmuggling
CostsalongtheSouthwestBorder,”OfficeofImmigrationStatistics,DepartmentofHomelandSecurity
WorkingPaper,November2010,https://www.dhs.gov/xlibrary/assets/statistics/publications/oissmuggling-wp.pdf.
48
ManuelaAngelucci,“U.S.BorderEnforcementandtheNetFlowofMexicanIllegalMigration,”Economic
DevelopmentandCulturalChange60(2012):311-57,GordonH.Hanson,RaymondRoberston,andAntonio
Spilimbergo,“DoesBorderEnforcementProtectU.S.WorkersfromIllegalImmigration?”ReviewofEconomicsand
Statistics,84,1(2002):73-92,GordonH.HansonandAntonioSpilimbergo,“IllegalImmigration,Border
Enforcement,andRelativeWages:EvidencefromApprehensionsattheU.S.-MexicoBorder,”AmericanEconomic
Review89,5(1999):1337-57,GordonH.HansonandCraigMcIntosh,“TheDemographyofMexicanMigrationto
theUnitedStates,”AmericanEconomicReview,99,2(2009):22-27,AlbertoDavila,JoseA.Pagan,andGokce
Soldemir,“TheShort-TermandLongTermDeterrenceEffectsofINSBorderandInteriorEnforcementon
UndocumentedImmigration,”JournalofEconomicBehaviorandOrganization49,2(2002):459-72,DouglasS.
MasseyandFernandoRiosema,“UndocumentedMigrationfromLatinAmericainanEraofRisingU.S.
Enforcement,”AnnalsoftheAmericanAcademyofPoliticalandSocialScience630(2010):137-61,DouglasS.
Massey,JorgeDurand,andKarenA.Pren,“ExplainingUndocumentedMigration,”InternationalMigrationReview
48(2014):1028-61.
49DoulasS.Massey,“ChainReaction:TheCausesandConsequencesofAmerica’sWaronImmigrants,”IZA
JulianSimonLectureSeries,(2011),http://www.iza.org/conference_files/amm2011/massey_d1244.pdf.
19
50
JeremySlack,DanielE.Martinez,ScottWhiteford,EmilyPeiffer,“InHarm’sWay:FamilySeparation,Immigration
EnforcementProgramsandSecurityontheU.S.-MexicoBorder,”JournalonMigrationandHumanSecurity3,2
(2015):109-128.
51
DouglasS.Massey,JorgeDurand,andKarenA.Pren,“WhyBorderEnforcementBackfired,”AmericanJournalof
Sociology121,5(2016):1558.
52
Ibid.
53JeremySlack,DanielE.Martinez,ScottWhiteford,EmilyPeiffer,“InHarm’sWay:FamilySeparation,Immigration
EnforcementProgramsandSecurityontheU.S.-MexicoBorder,”JournalonMigrationandHumanSecurity3,2
(2015):109-128.
54
DouglasS.Massey,JorgeDurand,andKarenA.Pren,“WhyBorderEnforcementBackfired,”AmericanJournalof
Sociology121,5(2016):1562-63.
55http://www.cato.org/blog/enforcement-didnt-end-unlawful-immigration-1950s-more-visas-did
56DorisMeissner,DonaldM.Kerwin,MuzaffarChisti,andClaireBergeron,“ImmigrationEnforcementinthe
UnitedStates:TheRiseofaFormidableMachinery,”MigrationPolicyInstituteReport,January2013,p.19,
http://www.migrationpolicy.org/research/immigration-enforcement-united-states-rise-formidablemachinery.
57DoulasS.Massey,“ChainReaction:TheCausesandConsequencesofAmerica’sWaronImmigrants,”IZA
JulianSimonLectureSeries,(2011):19,http://www.iza.org/conference_files/amm2011/massey_d1244.pdf.
20