It's also important to remember that 'mass migration' tends…

It's also important to remember that 'mass migration' tends to be a perception taken from media headlines and isn't always reflective of the broader picture. In Europe, for example, the peak of the refugee crisis in 2015 was notable but the numbers have since declined significantly. In the US, illegal border crossings have overall decreased over the past two decades, although there have been recent surges.