FAA Training vs. All The Rest
I'm sure there's no place else in the world that is training controllers at the rate the US FAA is doing. We're "cranking out" 1,500 - 1,700 new controller trainees a year and this will probably go on for the next 5 - 10 years.
Our system relies on the College Training Initiative (CTI) program which generates thousands of college graduates (AS and BS degrees) who are trained in the basics of ATC. We also draw from the military for experienced controllers. In some hard-to-staff areas, the FAA hires locals "off the streets". It is a huge effort and one like no other place on the planet.
The question, of course, is what level of quality are we maintaining? Time will tell.