The Trump administration is pressing ahead with building a wall along the nation’s southern border. President Trump often justifies the border wall by saying it will help deter crime.
But do border walls cut down on crime? Our research on the separation barrier erected by Israel in the West Bank suggests not.
Here’s how we did our research
In a recent paper, we studied whether the initial phase of wall construction in the West Bank, between 2000 and 2004, reduced vehicle thefts in Israel. During that period, the Israeli wall was partially constructed, much as is true for the U.S. border wall. We studied vehicle thefts because they are closely related to cross-border smuggling in the United States: About 80 percent of cars stolen in Israel are smuggled to the West Bank to be dismantled into spare parts, which are then sold back to Israeli car shops. Using Israel’s Freedom of Information Act, we obtained data from the Israeli police on all the vehicles stolen in each township, by month, as well as all the vehicle-theft-related arrests, including the detainee’s town of origin. We then tracked whether those thefts dropped as the border wall got closer to completion. Of course, stopping crime isn’t why Israel built the wall; it was fortified primarily to stop Palestinian suicide bombers from entering Israel during the Second Intifada uprising, which lasted from 2000 to 2005.
Much as Trump is doing with the United States’ wall, the Israelis built theirs in stages. The initial segments went up in mid-2002. By the end of 2004, Israel had fortified the border with the northern part of the West Bank, while the southern part was unprotected by the barrier, as you can see in the map below.
Staggered construction divided Israel into three zones. What we’ve marked as “north” was protected by the barrier; “south” wasn’t protected by the barrier; and “outer” included areas remote from the West Bank and unaffected by the barrier. We took advantage of the unequal progress across different segments of the wall to pinpoint whether and how much the wall deterred crime.
The West Bank wall displaced, rather than reduced, smuggling-related crime
A simple comparison of the protected area (“north”) and yet-to-be protected (“south”) areas between 2000 and 2004 suggested a large — but misleading — reduction in cross-border smuggling. This comparison is misleading because on closer inspection, we found that crime had simply been displaced.
To find that, we compared both the protected areas (“north”) and the unprotected areas (“south”) to the unaffected areas (“outer”). We found that vehicle theft in protected areas dropped by 41 percent compared with areas far from the West Bank, while increasing by 34 percent in unprotected towns. The overall reduction in criminal activity was close to zero. During construction, the wall appears to have displaced crime to unprotected areas. Crime rates went back to the pre-wall-period levels once the southern segment of the wall was completed in 2008.
For the protected towns, the wall reduced crime by making it both riskier and costlier to transport stolen vehicles to the West Bank. The reductions in car theft in each protected Israeli town strongly correlated with the increased length of the travel route between that town and the West Bank. On average, each additional kilometer that the wall forced smugglers to transport a stolen car wall decreased car thefts by about 6 percent.
Criminal activity adjusts after the wall goes up
First, the data on arrests on vehicle theft charges showed us that criminals do not appear to shift their activity from protected areas to unprotected towns. The increased crime in unprotected areas probably stems from local criminals becoming more active rather than from northern gangs traveling south.
Second, in the north, we found that although vehicle thefts dropped, other criminal activities — and in particular, burglaries — increased. That’s likely because to sell smaller stolen goods and valuables — electronics, jewelry, cash and the like — criminals could stay in Israel and didn’t have to transport goods to the West Bank.
In other words, while the wall made smuggling costlier and less likely, it also increased other illicit activities. Crime did not decrease.
Lessons for the U.S.-Mexico border wall
Constructing a southern border wall was one of Trump’s keystone campaign promises. So far, he’s made limited progress. By mid-2019, the Trump administration had added only 46.7 miles of new wall to the 654 miles of existing fortifications. Even if the administration succeeds in executing its plan, only 1,000 out of the 1,954 miles of the border will be fortified. It’s supposed to be a partial wall — just like the West Bank wall in the period that we focus on.
The current U.S.-Mexico wall is composed of fencing to stop people from crossing and obstacles to stop vehicles. These measures have not halted cross-border movement. Based on what we found from the West Bank wall, planned fortification along the U.S.-Mexico border is unlikely to result in less crime or less immigration.
Rather, if border fortification reduces migration or criminal activity in one region, it probably will be displaced to a neighboring area farther away, or prompt an increase in other types of criminal activity. A recent study of the U.S.-Mexico border wall suggests this may already be happening: The partially completed wall seems to have ignited inter-cartel competition in Mexico over alternative smuggling routes, leading to more murders in areas less affected by the barrier.
Do our conclusions about Israel’s border wall apply to the U.S. southern border? If walls are ever effective, they should stop the cross-border movement of vehicles, since it is easier for people than for cars to get around a physical barrier. But we find the Israeli wall to be ineffective even at stemming car smuggling. That suggests that a U.S. border wall isn’t likely to meaningfully limit the movement of people from Mexico into the United States.
Anna Getmansky (@anna_getmansky) is an assistant professor in the department of international relations at the London School of Economics and Political Science.
Guy Grossman (@guygrossman) is an associate professor in the department of political science at the University of Pennsylvania.
Austin L. Wright (@austinlwright) is an assistant professor at the University of Chicago Harris School of Public Policy.