There are not enough people in Central America for a 'national emergency' at the border

President Donald Trump has ordered 5,200 soldiers to settle at the US-Mexico border to repel what he calls an "invasion." However, the current migration wave in Central America is significantly smaller than the previous ones. And like the previous wave of migration from Mexico, it is not likely to last. There is simply not enough people in Central America.

"There is simply not much of the demographic potential for mass migrations from Central America," said Douglas Massey, who has spent the last three decades tracking migration as a co-founder of migration. Migration project in Mexico. "It is moving in the same direction as Mexico – towards an aging population with limited growth, only the basic population is much smaller. "

In figures, nothing looks like a "national emergency" at the border, as Trump has called him. The Border Patrol arrested fewer than 400,000 migrants last year. By comparison, this figure was 1.6 million in 2000, while Border Patrol employed about half of the number of agents it currently employs. Arrest rates over the last eight years have reached levels as low as those seen since the early 1970s.

The reason the arrests are so low is that massive Mexican migration to the United States ended ten years ago and shows no signs of recovery. Despite Trump's fury, he took office in conditions more favorable to intransigent immigration than any other president since Richard Nixon.

Neither the border patrol nor the immigration and customs control services can draw as much credit as they would like. The US financial crisis that erupted at the end of 2007 caused the decline of unauthorized Mexican migration by reducing the demand for labor. But perhaps more importantly, the crisis hit as the The Mexican baby boom era was blurring. In 1970, the fertility rate in Mexico rose to nearly seven children per woman. Today, it is around 2.2%, according to the World Bank.

The birth rate is important because most people who emigrate without permission in the United States do so before they turn 30. As the Mexican population has aged, the number of migrants attempting to travel illegally to the United States has declined.

The United States has witnessed a large-scale migration from Central America for decades, largely because of mass violence created by the civil wars of the era of the cold war and the authoritarian regimes that the The US government has played a key role in funding and manipulation.

The key change for unauthorized crossings in recent years is that the number of families in Central America and unaccompanied children increased by tens of thousands in 2014 and remained high. This year marks a record of arrests of families from Central American countries by border police, the vast majority of whom are from the El Salvador, Guatemala and Honduras countries, classified in the Northern Triangle.

But Central America follows the same demographic trajectory as Mexico. Together, the populations of these three countries total less than 31 million people. That's about one-third of the Mexican population in 2000, when border arrests peaked.

And these three countries have such a low birth rate. Guatemala is the highest, with nearly three births per woman, according to the World Bank. For Honduras, this figure is 2.45 per woman, and for El Salvador it is just under 2.1, a figure which hardly reaches the level that would replace the population of the country.

Mathematically, this virtually prevents the Northern Triangle from producing the high levels of sustained migration that the United States has seen from Mexico for decades.

"It's hard to believe that this will be a big flow for a long time," Nestor Rodriguez, a sociologist at the University of Texas at Austin, who is doing research on migration in Central America, told HuffPost. "The demographics are not there."

This phenomenon may already be happening in El Salvador. The Border Patrol arrested more than 27,000 Salvadoran families in 2016, as well as 17,500 unaccompanied children. This year, the number of families has halved and the number of children by nearly three quarters.

This trend may be partly explained by a decline in violence. The homicide rate in El Salvador is one of the highest in the world. This is one of the factors that pushed people to emigrate to the United States in above normal numbers from 2014 to 2016. However, in the last year, homicide rate dropped.

But the underlying reality is that El Salvador is a tiny country with a fertility rate below replacement level and has already lost about 1.4 million migrants in the United States since 1970 – about one-fifth of its total population.

"They have reached their peak," Rodriguez said of El Salvador. "Unless there is a significant increase in violence or civil war, we will not see any major upsurge."

The other two North Triangle countries have the ability to maintain higher levels of migration for longer periods. Honduras has been plagued by constant political instability since the 2009 coup, as well as high levels of violence and poverty. Guatemala has a larger population, a higher fertility rate and a large number of indigenous farmers struggling with crop failures – a trend according to some experts. related to climate change.

But these countries still face the same constraints as El Salvador. They are small. Their populations are aging. The number of migrants they send may increase or decrease from one year to the next, but in the long run, it will probably reach a maximum and decrease. And that will probably happen for demographic reasons that US policymakers do not control.

Although the increase in Central American migration that began in 2014 continues for years – which it will almost certainly not do – these numbers remain modest by historical standards.

"And if they were allowed to stay?", Sarah Bermeo, a political scientist at Duke University, wrote an opinion article during the summer on the Durham Herald-Sun. "In 2016, the US government arrested 224,854 people from El Salvador, Guatemala, and Honduras, less than one-tenth of the 1% of the US population. Even if the rate were maintained for a decade, it would still represent a much smaller share of the American population compared to waves of previous migrants such as Irish, Italians and Russian Jews. "