Dozens of families fleeing from Central America arrive at a bus station following their release from Customs and Border Protection in McAllen, Tex. (Spencer Platt/Getty Images)

While the Trump administration’s “zero-tolerance” immigration policy was causing a crisis on the U.S.-Mexico border, three members of Congress were introducing a bill to try to stop the flood of migrants coming in the first place. On June 22, Reps. Eliot Engel (D-N.Y.), Norma Torres (D-Calif.) and Adriano Espaillat (D-N.Y.) introduced the Central America Family Protection and Reunification Act, which aims to strengthen the State Department’s role in monitoring and addressing the root causes of migration from Guatemala, El Salvador and Honduras.

The bill places a special emphasis on migrant children, whose attempts to enter the United States spiked dramatically in 2014. Though it faces hurdles, if passed and signed, the law would require the State Department to study organized crime and gang-related offenses committed against children and devise a strategy to reduce gender-based violence. In other words, instead of sending young migrants back, this approach would consider how to keep them home in the first place.

Which brings up a question: Why are so many Central American children coming to the United States? Exactly what are the conditions that are pushing Central American child migrants north?

Here’s what the research says about why so many Central American children are migrating.

Mixed economic and violence-related motives

Experts tend to divide the things driving Central Americans to flee into two groups: economic factors and violence and insecurity. The first group includes the lack of economic opportunity, including a lack of jobs or inadequate opportunities for education. The second group includes violence and victimization, not just by gangs, other criminal groups and state security forces but at home as well.

Several studies show that violence in Central American countries is strongly related to migration. For example, a 2016 Latin American Public Opinion Project (LAPOP) survey found that those who’ve been crime victims more than once were significantly more likely to say they intended to migrate. Michael Clemens at the Center for Global Development found that between 2011 and 2016, across Honduras, Guatemala and El Salvador, each additional homicide per city is associated with nearly four more unaccompanied minors caught at the U.S. border. Sudden spikes in violence can be as powerful in pushing Central Americans out as long-term economic factors like poverty.

But it may not be easy to disentangle fleeing violence from seeking economic opportunity. In studies on unaccompanied child migrants by the U.N. High Commissioner for Refugees (UNHCR) and sociologist Matthew Lorenzen, most of those interviewed mentioned lack of opportunities at home — in ways that were intertwined with anxiety about crime and insecurity. As Lorenzen and social work professor Susan Schmidt note, Central American children escaping violence become economic migrants — because their families must pay off the debts incurred on their journey north. And for those fleeing gang extortions at work or gang recruitment at school, employment and education can’t be separated from the threat of violence.

Differences and similarities across countries

Within those two large reasons, however, there are key differences among Central America’s top three migrant-sending countries. In particular, Guatemalan children are leaving for different reasons than those fleeing to El Salvador and Honduras.

The majority of child migrants in all three countries mention economic motives like lack of opportunity and education. But roughly half of the children who flee El Salvador and Honduras say they’re also coming to the United States to reunite with their parents, according to the UNHCR, while only a quarter of Guatemalan child migrants say the same. Sociologists Katharine Donato and Blake Sisk find similar differences between the effects of parental migration on child migration when comparing Guatemala and El Salvador.

Salvadorans and Hondurans are also much more likely to say they’re fleeing gang and organized crime violence; 30 percent of Salvadorans and 36 percent of Hondurans  reported those as reasons (alone or alongside economic motives) in Lorenzen’s study — but only 8 percent of Guatemalans named violence as behind their decision to migrate. The LAPOP survey had similar results.

That shouldn’t be surprising; Guatemala has a significantly lower homicide rate, which has been trending downward now since 2009.

And yet violence is indeed driving children out of Guatemala. Within the UNCHR sample of unaccompanied child migrants, nearly a quarter of the Guatemalans cited abuse in the home — about the same percentages as what’s reported by Hondurans and Salvadorans.

Public, gang and organized crime violence get more attention. But domestic violence — which U.S. Attorney General Jeff Sessions declared on June 11 is no longer grounds for asylum — may still push children to migrate, even when you’d think the need to make a living was more significant.

What should be done?

The complex social and economic dynamics that push Central Americans to flee to the United States won’t be easily fixed. Violence and limited economic opportunities are deeply rooted in the region, growing from such structural factors as the region’s history of U.S.-involved violence and conflict, endemic political corruption and stagnant economies.

But looking at the research, we can conclude two things. First, migrants are fleeing each of these countries for quite different reasons. Guatemala, El Salvador and Honduras present different kinds of dangers and opportunities (or lack thereof) to its youngest citizens. There won’t be a one-size-fits-all solution; policymakers will need to consider the local nuances.

Second, migrants are fleeing their home countries for complex reasons. Asylum claims are adjudicated as if it’s possible to determine accurately who’s primarily fleeing violence and human rights threats, and who’s seeking economic opportunities. If the research tells us anything, it’s that the reasons Central American children are fleeing to the United States are far more complicated and intertwined than the discrete boxes on an asylum application might suggest.

Rachel A. Schwartz is a PhD candidate in political science at the University of Wisconsin–Madison. She previously coordinated programs on security and migration in Central America and Mexico at the Inter-American Dialogue.