The government insists that 'prison works' and plans to introduce a tougher sentencing policy for people convicted of violent crime.

政府坚持认为“关押有效”，并计划对暴力犯罪者实行更严厉的判刑政策。

《牛津词典》

Of course, prison works to the extent that those who are incarcerated cannot commit further crimes while they are banged up.

ECONOMIST: Prisons

Prison works to the extent that anyone in prison cannot commit a crime on the outside while they're in - absolutely fine.

BBC: News Online

Whether or not prison works as a crime-fighting tool, how much further down the road of ever more frequent imprisonment can America go?

ECONOMIST: Prisoners