This month, The Council on Foreign Relations, a non-partisan think tank, released a study entitled, “Managing Illegal Immigration to the United States.”
To determine overall trends in areas like apprehensions, the study relied on information from the Mexico Migration Project, a survey based on interviews with several hundred households in communities that are sources for migrants to the United States.
The CFR report confirms, with graphs like this in Figure 4, other reports that illegal migration fell through the 1990's and 2000's:
Although not a perfect science, apprehensions are a fundamental measurement to determine the overall “effective ratio” for different border sectors.
Effectiveness is at the center of the immigration debate because the Gang of Eight’s immigration proposal sets an overall goal of a 90% effective rate, which may be hard to meet.
Here's how the equation reads now: Effectiveness = (apprehensions + turn-backs) / (got-aways + apprehensions + turn-backs)
Turn-backs = People who fled back to Mexico, away from approaching U.S. agents along the border
Got-Aways = Crossers known or suspected to have evaded apprehension and entered the U.S.
But got-aways and turn-backs are based on visual observations, determined by cameras, agents in the field, and physical evidence of movement, i.e. footsteps.
It’s been recently shown that finding these visual clues isn't as simple as previously thought. High powered sensors on unmanned drones have recently found that the agency's numbers were high in got-aways, with agents catching just a fraction of the border crossers spotted.
This most recent study explores what the effective rate would look like if turn backs were subtracted from the equation. Again, here's full equation (Apprehensions + Turn backs)/ (Apprehensions + got aways +turn backs).
Without turn backs:
As for turn-backs, the study concludes: "Turn-backs should not be included in either the numerator or denominator of any ratio measuring law enforcement effectiveness."
Eliminating this measurement from the equation changes the overall numbers and suggests that the goals being set forth in the immigration debate might not be realistic.
The report authors say they are hoping to prompt a national conversation about what success should look like when it comes to a secure border. To provide a point of comparison, the authors analyzed the 866-mille border that divided East and West Germany during the Cold War.
That border had a 95 percent apprehension rate. But it was also lined with mines, and the guards had orders to shoot to kill crossers.
"And so people who are talking for instance about something close to 100 percent apprehension for the United States on the border with Mexico, that is just not realistically achievable," said report author Edward Alden, who is a Senior Fellow at the Council on Foreign Relations. "The Germans were willing to do things in the Cold War that the United States would never be willing to do."
The report estimates that replicating the ratio of border agents used on the inner-German border would require tripling the number of agents on the US-Mexico border, at a cost of an additional $6 billion a year.