Do Family Separation and Detention Deter Immigration?
By Tom K. Wong
Getty/Ilana Panich-Linsman/The Washington Post
A mother and her son spent nearly a year in the Karnes Residential
Facility, a for-profit immigrant detention center, Austin, TX, January 2017.
separates families is. In response to the growing number of arrivals of Central American families and unaccompanied children in 2014, for
example, the Karnes County Residential Center was converted from a civil detention facility into a family detention facility that July. Families
were also detained at a temporary facility in Artesia, New Mexico, before the South Texas Family Residential Center in Dilley, Texas, opened in
December 2014. The Obama administration’s expanded use of family detention represented a major immigration policy shift, considering that
the administration had largely abandoned the practice in the years prior to July 2014. When delivering remarks at the opening of the South
Texas Family Residential Center, then-DHS Secretary Jeh Johnson stated, “I believe this is an effective deterrent.”
To explore the question of whether the expanded use of family detention in July 2014 deterred subsequent arrivals of families, this analysis
evaluates changes over time—from October 2011 to June 2018—in the monthly number of U.S. Border Patrol apprehensions of families at the
southwest border. Apprehensions are widely used as an indicator of flows.
Using interrupted time series analysis (ITSA), this analysis estimates the relationship between the expanded use of family detention and the
monthly number of U.S. Border Patrol apprehensions of families at the southwest border. (see Appendix) The analysis finds that the number of
families arriving at the border before July 2014—when the Karnes County Residential Center was converted to a family facility—was
increasing. But there was no statistically significant decrease in apprehensions of families at the border after the widespread expansion of
family detention in July 2014.
Moreover, a series of models were run specifying pseudo-interventions—meaning different start dates for the expanded use of family
detention—to address the possibility that policy changes need time to take effect. The pseudo-interventions analyzed include the months
shortly after the conversion of the Karnes County Residential Center; the month of the opening of the South Texas Family Residential Center;
and the three months after the opening of the South Texas Family Residential Center. These models produce qualitatively similar results: The
expanded use of family detention is not statistically significantly related to decreases in the monthly number of U.S. Border Patrol
apprehensions of families at the southwest border. (Emphasis ours-Awiz)
Beginning in July 2017, as The New York Times and Vox reported, the Trump administration piloted a zero-tolerance policy wherein all
individuals caught attempting to enter the United States without authorization were referred to the U.S. Department of Justice for prosecution.
Parents migrating with their children were then separated from their children. In other words, the separation of children from their parents at the
southwest border started even before the administration’s blanket zero-tolerance policy officially began in April 2018. In March 2017, in
response to whether the Trump administration planned to separate children from their parents, current White House chief of staff John Kelly
stated, “[I]n order to deter more movement along this terribly dangerous network, I am considering exactly that.” Despite widespread outrage
over family separations, Attorney General Jeff Sessions reiterated the administration’s belief in the deterrent effect of family separation: “We
cannot and will not encourage people to bring their children or other children to the country unlawfully by giving them immunity in the process.”
The monthly number of U.S. Border Patrol apprehensions of families at the southwest border has not decreased as a result of family
separation. Figure 1 illustrates the relationship between the use of family separation and the monthly number of apprehensions while
controlling for the expanded use of family detention in July 2014. It shows that the monthly number of apprehensions was increasing before the
expanded use of family detention in July 2014, continued to increase after, and increased again after the zero-tolerance pilot in July 2017.
In response to broad public backlash over his administration’s policy of
separating children from their parents at the United States’ southwest
border, President Donald Trump signed an executive order in June 2018
that purports to replace family separation with potentially indefinite family
detention. Numerous Trump administration officials have supported such
policies under the belief that they would deter families from attempting to
enter the United States.
Internal memos from the U.S. Department of Homeland Security (DHS),
however, illustrate that the administration’s family separation policy has
not had its intended effect. A new analysis of data from a longer period of
time illustrates that family detention has not acted as a deterrent either.
Altogether, the data show that both family detention and family separation
policies have not deterred families from coming to the United States in
the past—and are unlikely to do so in the future.
Detaining families in response to increased arrivals along the southwest
border is not new, even if President Trump’s zero-tolerance policy that
Seven additional models were run specifying
pseudo-interventions, which include the
months during which the zero-tolerance pilot
was in effect—August 2017 to November
2017—as well as the three months after the
zero-tolerance pilot ended. These models
produce qualitatively similar results, wherein
instead of having a deterrent effect, the
monthly number of U.S. Border Patrol
apprehensions of families at the southwest
border increased significantly after the
Figure 1 also illustrates the strong seasonal
trends in the monthly number of
apprehensions at the southwest border. Even
after taking seasonal trends into account,
however, there is still no evidence that the
policies analyzed in this brief act as a
Figure 2 makes these seasonal trends
clearer. In 2014, for example, the monthly
number of U.S. Border Patrol apprehensions
of families at the border increased beginning
in late winter—specifically in February and
March—and continued to increase through
spring—particularly in April, May, and June—
before beginning to decline in July. The figure
also shows that a second peak may have
emerged in October, November, and
December 2017, but it is too soon to tell if this
seasonal trend will hold. This is because 2017 was the first year in the time series that saw large numbers of apprehensions of families
during these months. Notably, the seasonal summer decrease in family apprehensions appears to lag one month behind the seasonal
summer decrease in total apprehensions—including families, unaccompanied minors, individuals traveling alone, and others—which dips
beginning in June.
Because the data on the monthly number of family apprehensions at the southwest border exhibit seasonal trends, it is important to check
the robustness of the results using autoregressive integrated moving average (ARIMA) ITSA. ARIMA modeling allows one to evaluate the
extent to which an intervention has an effect on an outcome of interest that is independent from underlying time trends.
Even after taking seasonal trends into account, however, neither the expanded use of family detention nor the use of family separation is
statistically significantly related to decreases in the monthly number of family apprehensions. In other words, the data continue to show that
these policies do not act as deterrents to families attempting to enter the United States. Fifteen different models were run specifying
pseudo-interventions; these models produce qualitatively similar results.
The Obama administration used family detention in response to an increase in Central American families and unaccompanied children
arriving at the southwest border. The Trump administration has turned instead to family separation and potentially indefinite detention. Both
policies, however, have been shown to be ineffective deterrents.
Tom K. Wong is a senior fellow for Immigration Policy at the Center for American Progress and associate professor of Political Science at the
University of California, San Diego. His latest book is The Politics of Immigration: Partisanship, Demographic Change, and American