Donald Trump’s Mexican Border Wall Is a Moronic Idea

The data show that fences don’t keep migrants out — they just keep them from going home


Republican presidential candidate Donald Trump’s recently released proposal for immigration reform is simple: build a wall along the length of the U.S.-Mexico border, and make Mexico pay for it. Setting aside the issue of how the United States might make Mexico pay for a blatant monument to anti-Mexican sentiment, the idea is flat-out moronic, to use one of The Donald’s favorite adjectives, like asking the Mongolians to pay for the Great Wall of China.

In the first place, it’s not as if the border is undefended. The United States spends $3.7 billion per year to keep around 21,000 Border Patrol agents in the field, and another $3.2 billion on 23,000 inspectors at ports of entry along the border, a third of which has already been walled or fenced off. It is perhaps the most patrolled and highly defended border anywhere in the world, at least for two closely connected countries at peace with one another. Judging from the border, you’d never know Mexico was a friendly nation linked to the United States by a treaty agreement worth over half a trillion dollars in annual trade.

But a plan for more walls to further enhance border enforcement is moronic not only because it is expensive.

Abundant evidence also shows that money spent on border enforcement is worse than useless — it’s counterproductive.

Abundant evidence also shows that money spent on border enforcement is worse than useless — it’s counterproductive. For most of the 20th century, migration from Mexico was heavily circular, with male migrants moving back and forth across the border to earn money in the United States and then returning to Mexico to spend and invest at home. From 1965 to 1985, estimates indicate that 86 percent of undocumented entries were offset by departures, and the undocumented population grew slowly, rising to just under 3 million over two decades.

In 1986, however, Congress passed the Immigration Reform and Control Act, which kicked off a decades-long process of border militarization. It was passed during the Cold War, when President Ronald Reagan warned Americans that “terrorists and subversives” south of the border were “just two days’ driving time from Harlingen, Texas” and when his task force on terrorism stated that communist agents were ready to “feed on the anger and frustration of recent Central and South American immigrants who will not realize their own version of the American dream.”

Enforcement was further buttressed by the launching of Operation Blockade in El Paso, Texas, in 1993 and Operation Gatekeeper in San Diego, California, in 1994. These operations, led by the U.S. Border Patrol, erected a literal wall of enforcement resources at the two busiest U.S.-Mexico border crossings. They also diverted migratory flows away from these regions, through the Sonoran Desert, and into Arizona. This diversion greatly increased the costs and risks of undocumented border crossing: Since 1986, more than 7,000 migrants have died along the border, and the average cost of crossing has risen from $600 to $4,500, according to estimates from the Mexican Migration Project, which I co-direct.
Although the intent of border enforcement was to discourage migrants from coming to the United States, in practice it backfired, instead discouraging them from returning home to Mexico. Having experienced the risks and having paid the costs of gaining entry, undocumented men increasingly hunkered down and stayed in the United States, rather than circulating back to face the gantlet once more. As a result, the rate of return migration began to fall after 1986 and accelerated with the launching of the border operations in 1993 and 1994.

Because net migration equals the difference between those entering and leaving the United States, the falling rate of return produced a huge increase in the net volume of undocumented migration. Through the 1990s and early 2000s, in other words, the United States spent billions of dollars, only to double the rate of undocumented population growth. Not only that, but Operation Gatekeeper’s diversion of migrants away from California and into Arizona prompted them to continue onward to new destinations throughout the United States. Census data indicate that two-thirds of Mexican migrants who arrived between 1985 and 1990 went to California; by the 1995-to-2000 time period, that share had fallen to just one third, where it has since remained. Led by Mexicans, but also by Central Americans, the fastest-growing Latino populations are now in places like Georgia, North Carolina, and Iowa — not California.

In addition, as male migrants spent more time north of the border, they were increasingly joined by their wives and children. And then they started making babies. At present, almost 80 percent of the 5.1 million children of unauthorized immigrants were born in the United States and are U.S. citizens. In the end, the militarization of the border transformed what had been a circular flow of workers going overwhelmingly to just three states — California, Texas, and Illinois — into a much larger settled population of families living across all 50 U.S. states — not a good outcome for a policy whose goal was the limitation and control of immigration.

Doubling down on a failed policy of border militarization by adding more fences and walls is not only moronic because it would continue, at great cost, a demonstrably counterproductive strategy for restricting immigration — but it is also senseless because net undocumented migration from Mexico has stopped. Trump appears not to have received the memo. By the Department of Homeland Security’s own estimates, the total undocumented population peaked at 12 million in 2008, fell by a million by 2009, and since then has fluctuated around 11 million people.

Although the Great Recession may have been responsible for the sharp drop in 2008, undocumented Mexican migration had actually begun to decline around 2000 — not because of rising border enforcement, but because of Mexico’s demographic transition. Whereas the total fertility rate stood at 7.2 children per woman in 1965, by 2000 the Mexican fertility rate had fallen to 2.4; today, it stands at 2.3 children per woman, just above replacement level, yielding much less demographic pressure for migration to the United States.

The huge cohorts of Mexicans born in the 1960s were mainly responsible for the large number of undocumented migrants entering the United States during the 1980s, but the small cohorts born since 2000 have produced declining rates of labor force growth in Mexico, which has become an aging society. Migration follows a characteristic age pattern that rises in the teens, peaks in the early 20s, and falls to near zero by age 30. If people don’t migrate within that age range, they are very unlikely to make the journey later. What this means: The average age of Mexicans at risk of initiating undocumented migration has now pushed past the upper limit.

Although improving economic conditions would have, by now, led to a return of undocumented migrants if historical patterns still prevailed, this simply hasn’t happened. Instead, the number of apprehensions at the border is at its lowest point since 1973. And in 2014, for the first time, a majority of those caught were Central Americans — not Mexicans — who have long been a small part of the undocumented inflow, and amounted to little more than a rounding error when Mexican apprehensions were regularly exceeding 1 million per year. Fertility rates are also dropping rapidly in Central America. Given current demographic realities south of the border, where 85 percent of undocumented migrants originate, a return to the 1980s and 1990s is extremely unlikely.

While net undocumented migration from Mexico may have ceased, legal immigration continues apace.

While net undocumented migration from Mexico may have ceased, legal immigration continues apace. Over the past 10 years, the United States experienced 1.6 million entries by legal immigrants and 3.9 million entries by temporary workers from Mexico. These migrants increasingly circulate back and forth in response to changing conditions and opportunities in each country, while undocumented migrants are paradoxically the ones who are trapped north of the border, unable to return to Mexico for fear of not being able to return to family, friends, and lives in the north. Rather than attempting to repress migration that occurs as a natural consequence of ongoing economic integration in North America, a more reasonable policy would be to bring the flows aboveboard and manage them in ways that benefit both countries, while protecting the rights of citizens on both sides of the border.

The United States already has a sizable guest-worker program and supports a legal framework that allows for significant legal immigration from Mexico each year. And with net undocumented migration at zero, the border is as under control as it’s ever going to be. The only task remaining is finding a pathway to legal status for 11 million undocumented residents of the United States, giving them the freedom to come and go as they please and build a better life wherever they choose.

With few undocumented migrants entering and those already in the United States legalized, the problem of undocumented migration would be solved. This might be an unwelcome development for politicians who have grown used to using illegal migration as a sop to mobilize voters. But the reality is that undocumented migration has ended and won’t be coming back. Spending billions of dollars more on border enforcement to solve a problem that no longer exists is, umm, what’s the right word? Moronic.

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