Perhaps the location is only a side effect, while the true reason is the low supply of qualified coders. Why do corp lawyers command $400-600/hour? Why not to just hire a lawyer in India for $40/hour? Why not to hire a cheap accountant in Phillipines? Ah, right, the cheap options cost more in the long run and those who are competent have migrated to the US and now command the same 600/hour.