" Return flights south are often nearly empty, and some routes offer only one-way service. One of the airlines, Tijuana-based Avolar, estimates that 70% of its customers have the USA as their final destination."

I saved the best lines for last. It's almost funny.

the free market at work - with the willing help of the US government that absolutely refuses to secure the border.

Yep. I admire that they saw the opportunity within their own country. The consequences (for U.S.) aren't thrilling though.