This was addressed by Ronald D. Moore. In brief, the Earth is a garden paradise except for New Zealand, which is apparently overrun by rapscallions and ne'er-do-wells.

Q. Hey, Ron...if there is no crime on Earth, why are there established penal colonies in New Zealand? Hmmmmm??

RD.M: Actually, the only criminals left on Earth are in New Zealand so it only made sense to put the prison there.

_{^{AOL Chat}}

This was addressed by Trek writer/producer Ronald D. Moore. In brief, the Earth is a garden paradise except for New Zealand, which is apparently overrun by rapscallions and ne'er-do-wells.

Q. Hey, Ron...if there is no crime on Earth, why are there established penal colonies in New Zealand? Hmmmmm??

RD.M: Actually, the only criminals left on Earth are in New Zealand so it only made sense to put the prison there.

_{^{AOL Chat}}

It's possible he was joking here.