Why Physical Barriers Backfire: How Immigration Enforcement Deters Return and Increases Asylum Applications

• Published date: 01 December 2021
• Date: 01 December 2021
• DOI: http://doi.org/10.1177/00104140211024282
• Subject Matter: Articles

Article

Comparative Political Studies

2021, Vol. 54(14) 2611–2652

© The Author(s) 2021

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DOI: 10.1177/00104140211024282

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Why Physical Barriers

Backfire: How

Immigration

Enforcement Deters

Return and Increases

Asylum Applications

Justin Schon

1

and David Leblang

1

Abstract

What, if any, effect do physical barriers have on cross-border population

movements? The foundational claim that barriers reduce migration flows

remains unsupported. We conceptualize barriers as a tool of immigration

enforcement, which we contend is one form of state repression. State re-

pression could reduce mobilization (reduce immigration), have no effect on

mobilization (barriers as symbolic political tools), or increase mobilization

(backfire). We evaluate the relationship between barriers and cross-border

population movements using a global directed dyad-year dataset for the 1990–

2016 time period of all contiguous dyads and nearby non-contiguous dyads.

Using instrumental variables, we find that physical barriers actually increase

refugee flows, consistent with the “backfire effect”identified in research on

United States immigration enforcement policies on its Mexican border.

Furthermore, we find that state repression (immigration enforcement)

creates this “backfire effect”via a “sunk costs”problem that reduces

movements of people and increases movement of status from migrant to

refugee.

1

University of Virginia, Charlottesville, VA, USA

Corresponding Author:

Justin Schon, Department of Politics, University of Virginia, Charlottesville, VA 22901, USA.

Email: jss5yf@virginia.edu

Keywords

borders, migration, social movements, repression, asylum, refugees

Introduction

Donald Trump’s 2016 campaign was notably punctuated by campaign rallies

where his supporters chanted “Build the Wall!”While Trump’ssingle-minded

focus on border control and his overall stance on migration may have shocked

many observers, he is certainly not the only leader to use anti-immigrant and

anti-refugee rhetoric to generate political support for the construction of

physical barriers at a nation’s borders (Simmons & Kenwick, 2021). A quick

glance at history suggests that China’s construction of the Great Wall and

France’s development of the Maginot Line are examples that may prove the

rule. The creation and construction of border barriers became increasingly

popular following the end of the Cold War (Vallet, 2016) as politicians pointed

to walls as a means to increase security, decrease illegal smuggling, and,

importantly, reduce unwanted immigration (Avdan & Gelpi, 2016;Carter &

Poast, 2017;Hassner & Wittenberg, 2015). These security narratives are an

attempt to elicit an emotional response among the electorate by signaling that

the government is willing to reify boundaries between in-groups and out-

groups (Brown, 2010).

While barriers are constructed for political purposes, we know little about

whether these physical barriers are effective. Put simply, do barriers work?

While there is limited evidence that physical barriers improve security

(Linebarger & Braithwaite, 2020), they also reduce legal international trade

(Carter & Poast, 2020). The effect on migration is less clear: Getmanski et al.

(2019) conclude that walls, rather than preventing smuggling, just force

smugglers to find new routes. Jones (2016),Vallet (2016), and Longo (2017)

also reached somewhat mixed conclusions regarding the impact of border

walls on cross-border migration.

In a global economy where most mobility between contiguous countries is

circular—migrants crossing borders for temporary work and then returning

back to the homeland—we argue that border fortifications actually increase

migration. By making return difficult, border walls “deflect”population

movements from being temporary and circular to becoming one-way and

permanent. While the notion of barrier walls resulting in a deflection of

populations from temporary to permanent migration may seem counterin-

tuitive, it is consistent with some recent work examining the effect of visa

policies in Europe (e.g., Czaika & Hobolth, 2016) and border enforcement in

the United States (e.g., Massey et al., 2016). There are two mechanisms at

work: first, the construction of border walls and fortifications can, as noted

above, deter return as migrants realize that they may be unable to re-enter the

2612 Comparative Political Studies 54(14)

host country; second, walls may backfire by motivating a change in legal

status from migrant to asylum-seeker if there is a perception that asylum

claims may be more efficacious than turning to unauthorized entry.

We evaluate the “backfire”and “deflection”effects empirically through the

creation of a directed dyad-year dataset for the period 1990–2016. This di-

rected dyad sample is unique in that it includes not just contiguous countries—

countries that share a land or water border—but it also includes the four

closest non-contiguous origin countries for each destination. In this sample,

the United States, for example, is a destination country for El Salvador,

Honduras, Belize, and Guatemala as non-contiguous origin countries along

with Canada, Mexico, Russia, The Bahamas, and Cuba as contiguous

countries of origin. This approach is warranted as the overwhelming majority

of asylum claims, and unauthorized migrant flows originate from countries

that are reasonably spatially proximate to the destination country.

Because non-contiguous countries and the contiguous countries that

connect them—what we term “migration corridors”—contain legal and illegal

trade and migration routes, our empirical strategy is based on an instrumental

variable approach. The use of our instrument—a measure that exploits

geographic features of borders—enables us to obtain consistent and unbiased

estimates; it illustrates how earlier results are biased due to endogeneity. To

more accurately evaluate the “backfire”effect, we also employ instrumental

variable-mediation analysis to examine whether barriers increase migration

flows directly or via an increase in asylum applications. This allows us to

account for endogeneity and to distinguish between the effects of barriers on

the movements of people and the change in legal status.

This article makes several contributions to the literature. First, our theo-

retical approach combines two literatures: the scholarship on immigration

control with that of state repression. The state repression literature—work that

is utilized in studies of forced migration (e.g., Davenport et al., 2003)—is

often overlooked by scholars working on immigration control (e.g., Helbling

& Leblang, 2019) even though both literatures examine how state rules and

laws are used against those challenging existing power relationships. Second,

as noted, we show that immigration enforcement produces a “backfire”effect

which substantively means that the construction of border walls and forti-

fications actually increases cross-border migration flows. Third, we employ a

novel method—instrumental variable-mediation analysis—that allows us to

unpack the backfire effect into how border barriers affect the movement of

people and movement of status.

The remainder of this article proceeds as follows. First, we develop our

theoretical argument and show how refugee flows—our measure of cross-

border migration—can result from the movement of people or movement of

status. Next, we develop the hypothesis that border barriers produce a backfire

effect of higher refugee flows, as well as unpacking how the backfire effect

Schon and Leblang 2613